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(b) The reflected ray rotates through an angle , , the brightness of image by gathering more light from distant object., However, it increases aberrations particularly spherical., , (c) The reflected ray rotates through an angle 2, (d) The incident ray is fixed, , For a telescope with increase in length of the tube, magnification, decreases., In case of a telescope if object and final image are at infinity then :, f, D, m o , fe, d, , 5., , d, , D, , fo, , fe, , If we are given four convex lenses having focal lengths, , 6., , f1 f2 f3 f4 . For making a good telescope and microscope. We, choose the following lenses respectively., Telescope f1 (o), f4 (e ), Microscope f4 (o), f3 (e ), , 7., , monochromatic light of wavelength 5500 Å is called 1 lumen., , While solving the problems of photometry keep in mind., , , (As = R = 4L), 8., , R 1 1, L, , 1, R2 2, L2, , (b) 5 cm / sec, , (c), , (d) 15cm / sec, , 20cm / sec, , A light bulb is placed between two plane mirrors inclined at an, angle of 60. The number of images formed are, Orissa JEE 2003; MP PMT 2004; MP PET 2004], , The luminous flux of a source of (1/685) watt emitting, , RL, , (a) 10cm / sec, , SCRA 1994; AIIMS 1997; RPMT 1999; AIEEE 2002;, , If a parrot is sitting on the objective of a large telescope and we, look towards (or take a photograph)of distant astronomical object (say, moon) through it, the parrot will not be seen but the intensity of the, image will be slightly reduced as the parrot will act as obstruction to, light and will reduce the aperture of the objective., , A plane mirror is approaching you at a speed of 10 cm / sec You, can see your image in it. At what speed will your image approach, you, [CPMT 1974], , 9., , (a) 6, , (b) 2, , (c) 5, , (d) 4, , It is desired to photograph the image of an object placed at a, distance of 3m from the plane mirror. The camera which is at a, distance of 4.5m from the mirror should be focussed for a, distance of, [NCERT 1971], (a), , 3m, , (b) 4.5m, , (c), , 6m, , (d) 7.5m, , A thick plane mirror shows a number of images of the filament of, an electric bulb. Of these, the brightest image is the, (a) First, , (b) Second, , (c) Fourth, , (d) Last, , A man is 180cm tall and his eyes are 10cm below the top of his, head. In order to see his entire height right from toe to head, he, uses a plane mirror kept at a distance of 1m from him. The, minimum length of the plane mirror required is, [MP PMT 1993; DPMT 2001], , Plane Mirror, 1., , Two vertical plane mirrors are inclined at an angle of 60 with, each other. A ray of light travelling horizontally is reflected first, from one mirror and then from the other. The resultant deviation is, (a), , 2., , 60, , (b) 120, , (d) 240, (c) 180, A plane mirror reflects a pencil of light to form a real image. Then, the pencil of light incident on the mirror is, [MP PMT 1997; DCE 2001, 03], , 3., , 10., , 11., , (a) Parallel, (b) Convergent, (c) Divergent, (d) None of the above, What should be the angle between two plane mirrors so that, whatever be the angle of incidence, the incident ray and the, reflected ray from the two mirrors be parallel to each other, [KCET 1994; SCRA 1994], , (a), , (b) 90, , 120, , (d) 175, A plane mirror reflecting a ray of incident light is rotated through, an angle about an axis through the point of incidence in the, plane of the mirror perpendicular to the plane of incidence, then, , (c), 4., , 60, , (a) The reflected ray does not rotate, , 12., , (a) 180cm, , (b) 90cm, , (c), , (d) 170cm, , 85cm, , A person is in a room whose ceiling and two adjacent walls are, mirrors. How many images are formed [AFMC 2002], (a) 5, , (b) 6, , (c) 7, , (d) 8, , When a plane mirror is placed horizontally on a level ground at a, distance of 60m from the foot of a tower, the top of the tower and, its image in the mirror subtend an angle of 90 at the eye. The, height of the tower will be, [CPMT 1984], (a), , 30m, , (b) 60m, , (c), , 90m, , (d) 120m, , A ray of light incidents on a plane mirror at an angle of 30. The, deviation produced in the ray is, 30, , (b) 60, , 90CPMT 1991], (c) 1978;, [NCERT, , (d) 120, , (a), , [
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13., , A ray of light is incidenting normally on a plane mirror. The angle of, reflection will be, [MP PET 2000], (a), , 0, , (c) Will not be reflected, 14., , 23., , (b) 90, , [KCET (Engg.) 2001], , (d) None of the above, , When light wave suffers reflection at the interface from air to glass,, the change in phase of the reflected wave is equal to, , 24., , [CPMT 1991; J & KCET 2004], , 15., , 16., , 17., , 18., , (a) 0, , (b), , , 2, , (c) , , (d), , 2, , 25., , 26., , (a), , 90, , (b) 60, , (c), , 180, , (d) None of these, , (d) 80 cm, , An object is at a distance of 0.5 m in front of a plane mirror., Distance between the object and image is, [CPMT 2002], (a) 0.5 m, (b) 1 m, (c) 0.25 m, (d) 1.5 m, A man runs towards a mirror at a speed 15 m/s The speed of the, image relative to the man is, [Kerala PET 2002], (b) 30 ms 1, , (d) 20 ms 1, (c) 35 ms 1, The light reflected by a plane mirror may form a real image, [KCET (Engg. & Med.) 2002], , (a) If the rays incident on the mirror are diverging, , (a) None, , (b) 1, , (d) Under no circumstances, , (c) 2, , (d) 3, , 27., , When a plane mirror is rotated through an angle then the, reflected ray turns through the angle 2 then the size of the image, (a) Is doubled, , (b) Is halved, , (c) Remains the same, , (d) Becomes infinite, , A plane mirror produces a magnification of, , 28., , 1, , (b) 1, (d) Between 0 and , , 29., , A plane mirror makes an angle of 30 with horizontal. If a vertical, ray strikes the mirror, find the angle between mirror and reflected, ray, [RPET 1997], (a), , 30, , (b) 45, , (c), , 60, , (d) 90, , A watch shows time as 3 : 25 when seen through a mirror, time, appeared will be, [RPMT 1997; JIPMER 2001, 02], (a), , 8 : 35, , (b) 9 : 35, , (c), , 7 : 35, , (d) 8 : 25, , If an observer is walking away from the plane mirror with, 6m / sec. Then the velocity of the image with respect to observer, will be, [RPMT 1999], (a), , 6m / sec, , (c) 12m / sec, 22., , (c) 40 cm, , (b) If the rays incident on the mirror are converging, , (c) Zero, , 21., , (b) 20 cm, , Two plane mirrors are at right angles to each other. A man stands, between them and combs his hair with his right hand. In how many, of the images will he be seen using his right hand [MP PMT 1995; UPSEAT 2001], , (a), , 20., , (a) 60 cm, , (a) 15 ms 1, , A ray is reflected in turn by three plain mirrors mutually at right, angles to each other. The angle between the incident and the, reflected rays is, [Roorkee 1995], , [MP PET/PMT 1997], , 19., , A small object is placed 10 cm infront of a plane mirror. If you stand, behind the object 30 cm from the mirror and look at its image, the, distance focused for your eye will be, , 30., , Two plane mirrors are inclined at an angle of 72 0 . The number of, images of a point object placed between them will be [KCET (Engg. & Med.)1999;, (a) 2, , (b) 3, , (c) 4, , (d) 5, , To get three images of a single object, one should have two plane, mirrors at an angle of, [AIEEE 2003], (a) 30°, , (b) 60°, , (c) 90°, , (d) 150°, , A man of length h requires a mirror, to see his own complete image, of length at least equal to, [MP PET 2003], (a), , h, 4, , (b), , h, 3, , (c), , h, 2, , (d) h, , Two plane mirrors are at 45 to each other. If an object is placed, between them, then the number of images will be, [MP PMT 2003], , 31., , (b) 6m / sec, (d) 3m / sec, , (c) If the object is placed very close to the mirror, , (a) 5, , (b) 9, , (c) 7, , (d) 8, , A man having height 6 m. He observes image of 2 m height erect,, then mirror used is, [BCECE 2004], (a) Concave, (b) Convex, (c) Plane, , (a) 7.5 m/s, , (b) 15 m/s, , A light beam is being reflected by using two mirrors, as in a, periscope used in submarines. If one of the mirrors rotates by an, angle , the reflected light will deviate from its original path by the, angle, [UPSEAT 2004], , (c) 30 m/s, , (d) 45 m/s, , (a), , A man runs towards mirror at a speed of 15 m / s. What is the, speed of his image, [CBSE PMT 2000], , 32., , (d) None of these, , 2, , (b) 0 o
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(d) 4, , (c) , 33., , 34., , Focal length of a plane mirror is, (a) Zero, , (b) Infinite, , (c) Very less, , (d) Indefinite, , A ray of light is incident at 50° on the middle of one of the two, mirrors arranged at an angle of 60° between them. The ray then, touches the second mirror, get reflected back to the first mirror,, making an angle of incidence of [MP PET 2005], (a) 50°, , (b) 60°, , (c) 70°, , (d) 80°, , 9., , 10., , 1, times, n, , the object. The distance of the object from the mirror is, , (c), 2., , (n 1) f, , n 1, , f, n , , n 1 , (b) , f, n , , 11., , A diminished virtual image can be formed only in, (a) Plane mirror, , (b) A concave mirror, , (c) A convex mirror, , (d) Concave-parabolic mirror, , Which of the following could not produce a virtual image, , [MP PET 1993], , (a) Virtual, , (b) Real, , (c) Enlarged, , (d) Inverted, , In a concave mirror experiment, an object is placed at a distance x 1, , (a), , x1 x 2, , (b), , x1 x 2, , (c), , x1 x 2, 2, , (d), , x1, x2, , A convex mirror is used to form the image of an object. Then which, of the following statements is wrong, , (d) The image is real, 12., , Given a point source of light, which of the following can produce a, parallel beam of light, [CPMT 1974; KCET 2005], (a) Convex mirror, (b) Concave mirror, (c) Concave lens, , An object 5 cm tall is placed 1m from a concave spherical mirror, which has a radius of curvature of 20cm The size of the image is, , (d) Two plane mirrors inclined at an angle of 90, , (a), , 0.11cm, , (b) 0.50cm, , The image formed by a convex mirror of focal length 30cm is a, [MP PET 1993], quarter of the size of the object. The distance of the object from the, mirror is, , (c), , 0.55cm, , (d) 0.60cm, , (a), , The focal length of a concave mirror is 50cm. Where an object be, placed so that its image is two times and inverted, (a) 75 cm, , (b) 72 cm, , (c) 63 cm, , (d) 50 cm, , 13., , 2.3cm, , (c) 1cm, , 14., , 15., , The field of view is maximum for, (a) Plane mirror, , (b) Concave mirror, , (c) Convex mirror, , (d) Cylindrical mirror, , The focal length of a concave mirror is f and the distance from the, object to the principle focus is x. The ratio of the size of the image, to the size of the object is, [Kerala PET 2005], , (b) 90cm, (d) 60cm, , A boy stands straight infront of a mirror at a distance of 30cm, 1, away from it. He sees his erect image whose height is th of his, 5, real height. The mirror he is using is, [MP PMT 1993], , (b) 1.78 cm, (d) 0.8 cm, , 30cm, , (c) 120cm, , An object of size 7.5 cm is placed in front of a convex mirror of, , (a), , 8., , x2, , (c) The image is erect, , radius of curvature 25cm at a distance of 40cm. The size of the, image should be, , 7., , Image formed by a convex mirror is, , f2, , (b) The image is diminished in size, , (d) All the above can produce a virtual image, , 6., , (d), , [CPMT 1973], , (c) Concave mirror, , 5., , f, x, , (a) The image lies between the pole and the focus, , (a) Plane mirror, (b) Convex mirror, , 4., , (c), , f, x, , (d) (n 1) f, , [MP PMT 2002], , 3., , (b), , focus. The focal length of the mirror would be, , A convex mirror of focal length f forms an image which is, , (a), , fx, f, , from the focus and the image is formed at a distance x 2 from the, , Spherical Mirror, 1., , (a), , [RPMT 2000], , 16., , (a) Plane mirror, (b) Convex mirror, (c) Concave mirror, (d) Plano-convex mirror, A person sees his virtual image by holding a mirror very close to the, face. When he moves the mirror away from his face, the image, becomes inverted. What type of mirror he is using, (a) Plane mirror, (b) Convex mirror, (c) Concave mirror, (d) None of these, Which one of the following statements is true, (a) An object situated at the principle focus of a concave lens will, have its image formed at infinity, (b) Concave mirror can give diminished virtual image, (c) Given a point source of light, a convex mirror can produce a, parallel beam of light
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17., , (d) The virtual image formed in a plane mirror can be, photographed, The relation between the linear magnification m , the object, , 25., , (a) Diminished, upright, virtual, , distance u and the focal length f is, , 18., , 19., , m, , (c), , f u, m, f, , (b) Enlarged, upright, virtual, (b) m , , f, f u, , (c) Diminished, inverted, real, (d) Enlarged, upright, real, , f, (d) m , f u, , 26., , While using an electric bulb, the reflection for street lighting should, be from, (a) Concave mirror, (b) Convex mirror, (c) Cylindrical mirror, (d) Parabolic mirror, A concave mirror is used to focus the image of a flower on a nearby, well 120cm from the flower. If a lateral magnification of 16 is, desired, the distance of the flower from the mirror should be, (a), , 20., , f u, f, , (a), , 8 cm, , 27., , 28., , (b) Convex mirror, (d) Concave lens, , Real, inverted and same in size, Real, inverted and smaller, Virtual, erect and larger, Virtual, erect and smaller, , 5 cm, , (c) 10cm, 23., , (c), 24., , 40cm, , (a) Infinity, , (b), , (c), , (d) 2 f, , (b) 12cm, (d), , (b), , f /2, , f, , An object 1cm tall is placed 4 cm infront of a mirror. In order to, produce an upright image of 3cm height one needs a, , (d) Plane mirror of height 12cm, 29., , 20cm, , [AFMC 1995], , 60cm, , A convex mirror has a focal length f . A real object is placed at a, , (c) Concave mirror of radius of curvature 4 cm, , Radius of curvature of concave mirror is 40cm and the size of, image is twice as that of object, then the object distance is, , (a), , (d) Concave mirror, , (b) Concave mirror of radius of curvature 12cm, , A virtual image three times the size of the object is obtained with a, concave mirror of radius of curvature 36cm. The distance of the, object from the mirror is, [MP PET 1986], (a), , (c) Convex mirror, , (a) Convex mirror of radius of curvature 12cm, , [MP PET 1986; MP PMT/PET 1998], , 22., , (b) Concave lens, , [MP PET 1986], , An object is placed 40cm from a concave mirror of focal length, 20cm. The image formed is, (a), (b), (c), (d), , (a) Convex lens, , distance f in front of it from the pole produces an image at, , [MP PMT 1986], , 21., , Which of the following form(s) a virtual and erect image for all, positions of the object, [IIT-JEE 1996], , (b) 12cm, , (c) 80cm, (d) 120cm, A virtual image larger than the object can be obtained by, (a) Concave mirror, (c) Plane mirror, , If an object is placed 10cm infront of a concave mirror of focal, [MP PMT 1995], length 20cm, the image will be, , Match List I with List II and select the correct answer using the, codes given below the lists :, [SCRA 1998], List I, , List II, , (Position of the object), , (Magnification), , (I) An object is placed at focus, before a convex mirror, (II) An object is placed at, centre of curvature before a, concave mirror, (III) An object is placed at, focus before a concave mirror, (IV) An object is placed at, centre of curvature before a, convex mirror, , (A) Magnification is , , 20cm, , (B) Magnification is 0 .5, (C) Magnification is 1, (D) Magnification is – 1, , (E) Magnification is 0.33, Codes :, , (d) 30cm, , All of the following statements are correct except, [Manipal MEE 1995], , (a) The magnification produced by a convex mirror is always less, than one, , 30., , (b) A virtual, erect, same-sized image can be obtained using a, plane mirror, , (b) I-A, II-D, III-C, IV-B, , (c) I-C, II-B, III-A, IV-E, , (d) I-B, II-E, III-D, IV-C, , A concave mirror gives an image three times as large as the object, placed at a distance of 20cm from it. For the image to be real, the, focal length should be, [SCRA 1998; JIPMER 2000], , (c) A virtual, erect, magnified image can be formed using a, concave mirror, (d) A real, inverted, same-sized image can be formed using a, convex mirror, , (a) I-B, II-D, III-A, IV-E, , 31., , (a) 10cm, , (b) 15cm, , (c), , (d) 30cm, , 20cm, , The minimum distance between the object and its real image for, concave mirror is, [RPMT 1999], (a) f, , (b) 2f
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32., , (c) 4f, (d) Zero, An object is placed at 20cm from a convex mirror of focal length, 10 cm. The image formed by the mirror is, , (c) 4 cm, 41., , [JIPMER 1999], , 42., , (a) Real and at 20 cm from the mirror, (b) Virtual and at 20 cm from the mirror, (c) Virtual and at 20 / 3 cm from the mirror, , 33., , Convergence of concave mirror can be decreased by dipping in, (a) Water, (b) Oil, (c) Both, (d) None of these, What will be the height of image when an object of 2 mm is placed, on the axis of a convex mirror at a distance 20 cm of radius of, [Orissa PMT 2004], curvature 40 cm, (b) 10 mm, (a) 20 mm, (c) 6 mm, , (d) Real and at 20 / 3 cm from the mirror, , 43., , Image formed by a concave mirror of focal length 6 cm, is 3 times, of the object, then the distance of object from mirror is, [RPMT 2000], , is moved by 0.1 cm towards the mirror, the image will shift by, about, (a), , [MP PMT 2000], , 44., , (c), , (b) 8 cm, (a) – 4 cm, (c) 6 cm, (d) 12 cm, A concave mirror of focal length f (in air) is immersed in water, ( 4 / 3 ). The focal length of the mirror in water will be, , 0.4 cm away from the mirror, , (b) 0.4 cm towards the mirror, 0.8 cm away from the mirror, , (a), , f, , (b), , 4, f, 3, , (c), , 3, f, 4, , (d), , 7, f, 3, , (d) 0.8 cm towards the mirror, , 35., , 36., , 37., , Under which of the following conditions will a convex mirror of, focal length f produce an image that is erect, diminished and virtual, (a) Only when 2f > u > f, (b) Only when u = f, (c) Only when u < f, (d) Always, The focal length of a convex mirror is 20 cm its radius of curvature, will be, [MP PMT 2001], , Refraction, of Light at Plane Surfaces, [AMU (Engg.) 2001], 1., , 39., , 40., , To an observer on the earth the stars appear to twinkle. This can be, ascribed to, [CPMT 1972, 74; AFMC 1995], , (a) The fact that stars do not emit light continuously, , (a) 10 cm, , (b) 20 cm, , (b) Frequent absorption of star light by their own atmosphere, , (c) 30 cm, , (d) 40 cm, , (c) Frequent absorption of star light by the earth's atmosphere, , A concave mirror of focal length 15 cm forms an image having twice, the linear dimensions of the object. The position of the object when, the image is virtual will be, (a) 22.5 cm, , (b) 7.5 cm, , (c) 30 cm, , (d) 45 cm, , (d) The refractive index fluctuations in the earth's atmosphere, 2., , A point object is placed at a distance of 30 cm from a convex mirror, of focal length 30cm. The image will form at, (a) Infinity, (b) Focus, (c) Pole, (d) 15 cm behind the mirror, An object 2.5 cm high is placed at a distance of 10 cm from a, concave mirror of radius of curvature 30 cm The size of the image, is, [BVP 2003], (a) 9.2 cm, (b) 10.5 cm, (c) 5.6 cm, (d) 7.5 cm, For a real object, which of the following can produced a real image, (a) Plane mirror, , (b) Concave lens, , (c) Convex mirror, , (d) Concave mirror, , An object of length 6 cm is placed on the principle axis of a, concave mirror of focal length f at a distance of 4f. The length of, the image will be, [MP PET 2003], (a) 2 cm, , (b) 12 cm, , The ratio of the refractive index of red light to blue light in air is, (a), (b), (c), (d), , [JIPMER 2002], , 38., , (d) 1 mm, , A point object is placed at a distance of 10 cm and its real image is, formed at a distance of 20 cm from a concave mirror. If the object, , 34., , (d) 1.2 cm, , 3., , 4., , Less than unity, Equal to unity, Greater than unity, Less as well as greater than unity depending upon the, experimental arrangement, The refractive index of a piece of transparent quartz is the greatest, for, [MP PET 1985, 94], , (a) Red light, , (b) Violet light, , (c) Green light, , (d) Yellow light, , The refractive index of a certain glass is 1.5 for light whose, wavelength in vacuum is 6000 Å. The wavelength of this light when, it passes through glass is, [NCERT 1979; CBSE PMT 1993;, MP PET 1985, 89], , 5., , [Orissa, (a) 4000, Å JEE 2003], (b) 6000 Å, (c) 9000 Å, (d) 15000 Å, When light travels from one medium to the other of which the, refractive index is different, then which of the following will change, [MP PMT 1986; AMU 2001; BVP 2003], , (a) Frequency, wavelength and velocity, (b) Frequency and wavelength, (c) Frequency and velocity
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(d) Wavelength and velocity, 6., , 14., , A light wave has a frequency of 4 1014 Hz and a wavelength of, 5 10 7 meters in a medium. The refractive index of the medium, is, [MP PMT 1989], , 7., , (a) 1.5, , (b) 1.33, , (c) 1.0, , (d) 0.66, , 15., , How much water should be filled in a container 21 cm in height, so, that it appears half filled when viewed from the top of the container, (given that a 4 / 3 ), [MP PMT 1989], , 8., , (a) 8.0 cm, , (b) 10.5 cm, , (c) 12.0 cm, , (d) None of the above, , 16., , Light of different colours propagates through air, (a) With the velocity of air, , A rectangular tank of depth 8 meter is full of water ( 4 / 3 ),, the bottom is seen at the depth [MP PMT 1987], (a) 6 m, (b) 8/3 m, (c) 8 cm, (d) 10 cm, A vessel of depth 2d cm is half filled with a liquid of refractive index, 1 and the upper half with a liquid of refractive index 2 . The, apparent depth of the vessel seen perpendicularly is, (a), , , d 1 2, 1 2, , (c), , 1, 1 , , 2d , , , , , 2 , 1, , 1, 1 , , (b) d , , , , , 2 , 1, , , , , , , 1, (d) 2d , 1 2, , , , , , , A beam of light is converging towards a point I on a screen. A, plane glass plate whose thickness in the direction of the beam = t ,, refractive index = , is introduced in the path of the beam. The, convergence point is shifted by, [MNR 1987], , (b) With different velocities, (c) With the velocity of sound, , (a), , (d) Having the equal velocities, 9., , Monochromatic light is refracted from air into the glass of refractive, index . The ratio of the wavelength of incident and refracted, waves is, , 10., , 11., , 17., , [NCERT 1976; MP PET 1994; CBSE PMT 1996;, KCET 1994; MP PMT 1999, 2001], , :1, , (d) 1 : 1, (a), , A monochromatic beam of light passes from a denser medium into a, rarer medium. As a result, [CPMT 1972], (a) Its velocity increases, , (b) Its velocity decreases, , (c) Its frequency decreases, , (d) Its wavelength decreases, , 18., , Refractive index for a material for infrared light is, (a) Equal to that of ultraviolet light, (c) Equal to that for red colour of light, 19., , The index of refraction of diamond is 2.0, velocity of light in, diamond in cm/second is approximately, [CPMT 1975; MNR 1987; UPSEAT 2000], , 13., , (a), , 6 1010, , (b) 3.0 1010, , (c), , 2 1010, , (d) 1.5 1010, , A beam of light propagating in medium A with index of refraction n, (A) passes across an interface into medium B with index of, refraction n(B). The angle of incidence is greater than the angle of, refraction; v(A) and v(B) denotes the speed of light in A and B. Then, which of the following is true, (a) v(A) > v(B) and n(A) > n(B), (b) v(A) > v(B) and n(A) < n(B), (c) v(A) < v(B) and n(A) > n(B), (d) v(A) < v(B) and n(A) < n(B), , (b) tnc, , nt, tc, (d), c, n, When a light wave goes from air into water,, remains unchanged is its, , the quality that, , [AMU 1995; MNR 1985, 95; KCET 1993; CPMT 1990, 97; MP PET 1991, 2000,, 02; UPSEAT 1999, 2000;, AFMC 1993, 98, 2003; RPET 1996, 2000, 03;, RPMT 1999, 2000; DCE 2001; BHU 2001], , (b) Less than for ultraviolet light, (d) Greater than that for ultraviolet light, , t, nc, , (c), , [CPMT 1984], , 12., , , , 1, 1, t 1 nearer, (d) t 1 nearer, , , , , , , Light travels through a glass plate of thickness t and having, refractive index n. If c is the velocity of light in vacuum, the time, taken by the light to travel this thickness of glass is, , (b) 1 : 2, , (a) 1 : , , , 1, (b) t 1 away, , , , , (c), , [JIPMER 2000; MP PMT 1996, 2003], , (c), , , 1, t 1 away, , , , , (a) Speed, (b) Amplitude, (c) Frequency, (d) Wavelength, Light takes 8 min 20 sec to reach from sun on the earth. If the, whole atmosphere is filled with water, the light will take the time, ( a w 4 / 3 ), (a) 8 min 20 sec, (c) 6 min 11 sec, , 20., , The length of the optical path of two media in contact of length d1, and d 2 of refractive indices, , 21., , (b) 8 min, (d) 11 min 6 sec, , 1 and 2 respectively, is, , (a), , 1d1 2d 2, , (b) 1d 2 2d1, , (c), , 1 2, , d1 d 2, , (d), , d1 d 2, , 1 2, , Immiscible transparent liquids A, B, C, D and E are placed in a, rectangular container of glass with the liquids making layers, according to their densities. The refractive index of the liquids are, shown in the adjoining diagram. The container is illuminated from, the side and a small piece of glass having refractive index 1.61 is
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(b) Will be reflected back into the glass, , gently dropped into the liquid layer. The glass piece as it descends, downwards will not be visible in, [CPMT 1986], (a) Liquid A and B only, , A, , 1.51, , (b) Liquid C only, , B, , 1.53, , C, , 1.61, , D, E, , 1.52, , (c) Liquid D and E only, (d) Liquid A, B, D and E, 22., , (c) Will be absorbed, (d) Will emerge into the air with an angle of refraction equal to, 90°, 29., , If 0 and 0 are respectively, the electric permittivity and the, magnetic permeability of free space, and the corresponding, quantities in a medium, the refractive index of the medium is, , 1.65, , The refractive indices of glass and water w.r.t. air are 3/2 and 4/3, respectively. The refractive index of glass w.r.t. water will be, , [IIT-JEE 1982; MP PET 1995; CBSE PMT 1997], , [MNR 1990; JIPMER 1997, 2000; MP PET 2000], , 23., , (a) 8/9, , (b) 9/8, , (c) 7/6, , (d) None of these, , If, , ij, , (c), 24., , , 0 0, , (b), , (c), , 0 0, , , (d), , represents refractive index when a light ray goes from, , medium i to medium j, then the product 2 1 3 2 4 3 is equal, to, [CBSE PMT 1990], (a), , (a), , 3 1, , (b), , 1, , (d), , 1 4, , 30., , 3 2, 4 2, , The wavelength of light diminishes times ( 1.33 for water), in a medium. A diver from inside water looks at an object whose, natural colour is green. He sees the object as, , 31., , , 0 0, 0, 0, , A beam of monochromatic blue light of wavelength 4200Å in air, travels in water ( 4 / 3 ). Its wavelength in water will be, (a) 2800 Å, , (b) 5600 Å, , (c) 3150 Å, , (d) 4000 Å, , If 0 be the relative permeability and K 0 the dielectric constant, of a medium, its refractive index is given by, [MNR 1995], , [CPMT 1990; MNR 1998], , 25., , (a) Green, , (b) Blue, , (c) Yellow, , (d) Red, , 0 K0, , Ray optics fails when, , 0 K 0, , (c), , (a) The size of the obstacle is 5 cm, 32., , (b) The size of the obstacle is 3 cm, (c) The size of the obstacle is less than the wavelength of light, , (b), , 1, , 0 K0, , (d) 0 K0, , If the speed of light in vacuum is C m / sec, then the velocity of, light in a medium of refractive index 1.5, [NCERT 1977; MP PMT 1984; CPMT 2002], , (d) (a) and (b) both, 26., , 1, , (a), , (a) Is 1.5 C, , When light travels from air to water and from water to glass, again, from glass to CO 2 gas and finally through air. The relation, between their refractive indices will be given by, (a), , a nw, , wngl glngas gasna 1, , (b), , a nw, , wngl gasngl glna 1, , (c), , a nw, , wngl glngas 1, , (c) Is, 33., , C, 1 .5, , (b) Is C, (d) Can have any velocity, , In the adjoining diagram, a wavefront AB, moving in air is incident, on a plane glass surface XY. Its position CD after refraction through, a glass slab is shown also along with the normals drawn at A and D., The refractive index of glass with respect to air ( 1 ) will be, equal to, , (d) There is no such relation, 27., , 28., , [CPMT 1988; DPMT 1999], , For a colour of light the wavelength for air is 6000 Å and in water, the wavelength is 4500 Å. Then the speed of light in water will be, 2.25 10 8 m/s, , (a), , 5. 1014 m / s, , (b), , (c), , 4.0 10 8 m/s, , (d) Zero, , A ray of light travelling inside a rectangular glass block of refractive, index 2 is incident on the glass–air surface at an angle of, incidence of 45°. The refractive index of air is 1. Under these, conditions the ray, [CPMT 1972], (a) Will emerge into the air without any deviation, , 34., , (a), , sin, sin ', , (b), , sin, sin ', , (c), , sin ', sin, , (d), , AB, CD, , B, , X, , A, , , , , , , , , D, , Y, , C, , When light enters from air to water, then its, [MP PMT 1994; MP PET 1996], , [
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(a) Frequency increases and speed decreases, , 42., , (b) Frequency is same but the wavelength is smaller in water than, in air, (c) Frequency is same but the wavelength in water is greater than, in air, , 43., , [IIT 1980; CBSE PMT 1992; MP PET 1999;, MP PMT 1999; RPMT 1997, 2000, 03; MH CET 2004], , (d) Frequency decreases and wavelength is smaller in water than in, air, 35., , KCET 1994; 2000], , (a), (c), , 36., , (a), (b), (c), (d), , On a glass plate a light wave is incident at an angle of 60°. If the, reflected and the refracted waves are mutually perpendicular, the, refractive index of material is, [MP PMT 1994; Haryana CEE 1996;, , 3, 2, , (b), , 3, 2, , (d), , 44., , 3, , (c), , 3, 4, and refractive index of water is . If, 2, 3, , 45., , 2.25 10 8 m/s, , (a), , 2.67 10 8 m/s, , (b), , (c), , 1.78 10 8 m/s, , (d) 1.50 10 8 m/s, , 46., , Monochromatic light of frequency 5 1014 Hz travelling in vacuum, enters a medium of refractive index 1.5. Its wavelength in the, medium is, , 39., , (a) 4000 Å, , (b) 5000 Å, , (c) 6000 Å, , (d) 5500 Å, , 41., , (a), , a r, , a w r , , (b), , a r, , r w w a, , (c), , a r, , r a 0, , (d), , a r, , / w r a w, , (b) 0.167 10 7 s, (d) 1.0 10 10 s, , (b) n / h, , (c) h, , (d) hn, , On heating a liquid, the refractive index generally, , (c) Does not change, , 47., , 48., , 49., , If î denotes a unit vector along incident light ray, r̂ a unit vector, along refracted ray into a medium of refractive index and n̂, unit vector normal to boundary of medium directed towards, incident medium, then law of refraction is, (a) ˆi . nˆ (rˆ . nˆ ), , (b) ˆi nˆ (nˆ rˆ ), , (c) ˆi nˆ (rˆ nˆ ), , (d) (ˆi nˆ ) rˆ nˆ, , The bottom of a container filled with liquid appear slightly raised, because of, [RPMT 1997], (a) Refraction, , (b) Interference, , (c) Diffraction, , (d) Reflection, , The speed of light in air is 3 10 8 m / s . What will be its speed in, diamond whose refractive index is 2.4, [KCET 1993], , (a), , The time taken by sunlight to cross a 5 mm thick glass plate, [MP PMT/PET 1998; BHU 2005], ( 3 / 2 ) is, , 2.5 10 10 s, , (a) h / n, , [EAMCET (Engg.) 1995], , (a) The wavelength of red light is greater than the wavelength of, green light, (b) The wavelength of blue light is smaller than the wavelength of, orange light, (c) The frequency of green light is greater than the frequency of, blue light, (d) The frequency of violet light is greater than the frequency of, blue light, Which of the following is a correct relation, [MP PET 1997], , (c), , A man standing in a swimming pool looks at a stone lying at the, bottom. The depth of the swimming pool is h. At what distance, from the surface of water is the image of the stone formed (Line of, vision is normal; Refractive index of water is n), , (b) Increases or decreases depending on the rate of heating, , (a) 7200 Å, (b) 4800 Å, (c) 10800 Å, (d) 7201.5 Å, Which of the following is not a correct statement, , –10, , (b) 1.5, , (d) Increases, , Light of wavelength is 7200 Å in air. It has a wavelength in glass, ( 1.5 ) equal to, [DCE 1999], , (a) 0.25 10 s, , 10, 9, , 9, 10, , [KCET 1994], , [MP PET 1997], , 40., , (b), , (a) Decreases, , [MP PET/ PMT 1995; Pb. PET 2003], , 38., , A mark at the bottom of a liquid appears to rise by 0.1 m. The depth, of the liquid is 1 m. The refractive index of the liquid is, , 1, , the speed of light in glass is 2.00 10 8 m/s, the speed in water, will be, [MP PMT 1994; RPMT 1997], , 37., , Its wavelength and frequency both increase, Its wavelength increases but frequency remains unchanged, Its wavelength decreases but frequency remains unchanged, Its wavelength and frequency both decrease, , (a) 1.33, , 3, , Refractive index of glass is, , The distance travelled by light in glass (refractive index =1.5) in a, nanosecond will be, [MP PET 1999], (b) 40 cm, (a) 45 cm, (c) 30 cm, (d) 20 cm, When light is refracted from air into glass, , 3 10 8 m / s, , (c) 1.25 10 m/s, 8, , 50., , (b) 332 m / s, (d) 7.2 10 8 m / s, , Time taken by the sunlight to pass through a window of thickness 4, mm whose refractive index is 1.5 is, [CBSE PMT 1993]
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51., , (a), , 2 10 8 sec, , (b), , 2 10 8 sec, , (a) 1.96 10 8 m/s, , (c), , 2 10 11 sec, , (d), , 2 1011 sec, , (c), , (b) 2.12 10 8 m / s, , 3.18 10 8 m / s, , (d) 3.33 18 8 m / s, , Ray optics is valid, when characteristic dimensions are, [CBSE PMT 1994; CPMT 2001], , 59., , Absolute refractive indices of glass and water are, ratio of velocity of light in glass and water will be, , (a) Of the same order as the wavelength of light, , [UPSEAT 1999], , (b) Much smaller than the wavelength of light, (c) Of the order of one millimetre, (d) Much larger than the wavelength of light, 52., , 53., , 54., , The refractive index of water is 1.33. What will be the speed of light, in water, [CBSE PMT 1996; KCET 1998], (a), , 3 10 8 m / s, , (b), , (c), , 4 10, , (d) 1.33 10 m/s, , 8, , m/s, , 60., , (a) 4 : 3, , (b) 8 : 7, , (c) 8 : 9, , (d) 3 : 4, , The ratio of thickness of plates of two transparent mediums A and B, is 6 : 4. If light takes equal time in passing through them, then, refractive index of B with respect to A will be, , 2.25 10 8 m / s, , [UPSEAT 1999], , 8, , The time required to pass the light through a glass slab of 2 mm, [AFMC 1997; MH CET 2002, 04], thick is ( glass 1.5 ), , 61., , (a) 1.4, , (b) 1.5, , (c) 1.75, , (d) 1.33, , (a) 10 5 s, , (b) 10 11 s, , The refractive index of water and glass with respect to air is 1.3 and, 1.5 respectively. Then the refractive index of glass with respect to, water is, [MH CET (Med.) 1999], , (c) 10 9 s, , (d) 10 13 s, , (a), , 2 .6, 1 .5, , (b), , 1 .5, 2 .6, , (c), , 1 .3, 1 .5, , (d), , 1 .5, 1 .3, , The refractive index of water with respect to air is 4 / 3 and the, refractive index of glass with respect to air is 3/2. The refractive, index of water with respect to glass is, [BHU 1997; JIPMER 2000], , 55., , (a), , 9, 8, , (b), , (c), , 1, 2, , (d) 2, , 62., , 8, 9, , Electromagnetic radiation of frequency n, wavelength , travelling, with velocity v in air, enters a glass slab of refractive index . The, frequency, wavelength and velocity of light in the glass slab will be, respectively, , 63., , A tank is filled with benzene to a height of 120 mm. The apparent, depth of a needle lying at a bottom of the tank is measured by a, microscope to be 80 mm. The refractive index of benzene is, (a) 1.5, , (b) 2.5, , (c) 3.5, , (d) 4.5, , Each quarter of a vessel of depth H is filled with liquids of the, refractive indices n , n , n and n from the bottom respectively. The, apparent depth of the vessel when looked normally is, 1, , [CBSE PMT 1997], , 56., , n v, , ,, , (a), , , , (c), , n,,, , v, , , , (b) n,, (d), , n, , , , v, ,, , ,, , What is the time taken (in seconds) to cross a glass of thickness 4, , mm and = 3 by light, 11, , (a), , 4 10, , [BHU 1998;, , (c), , 16 10 11, , (b), , 2 10 11, , (c), 64., , 2, , 3, , 4, , H (n1 n2 n3 n4 ), 4, , (b), , (n1 n 2 n 3 n 4 ), 4H, , (d), , A plane glass slab is kept over various coloured letters, the letter, which appears least raised is, (a) Blue, , (b) Violet, , (c) Green, , (d) Red, , 1, 1, 1, 1, H , , , n1 n2 n3 n4, 4, , , , , , , 1, 1, 1, 1, H , , , n1 n2 n3 n4, 2, , , , , , , A ray of light passes through four transparent media with refractive, indices 1 . 2 3 , and 4 as shown in the figure. The surfaces of, all media are parallel. If the emergent ray CD is parallel to the, incident ray AB, we must have, [IIT-JEE (Screening) 2001], , (d) 8 10 10, , [J & K CET 2004; BHU 1998, 05], , 58., , (a), , , ,v, , , Pb. PMT 1999, 2001; MH CET 2000; MP PET 2001], , 57., , 3, 4, and, . The, 2, 3, , (a), , 1 2, , (b) 2 3, (c), , 3 4, , 1, B, , 2, , D, 4, , 3, C, , (d) 4 1, A, A ray of light is incident on the surface of separation of a medium, 65., The reason of seeing the Sun a little before the sunrise is, at an angle 45° and is refracted in the medium at an angle 30°., What will be the velocity of light in the medium[AFMC 1998; MH CET (Med.) 1999], [MP PMT 2001; Orissa JEE 2003]
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66., , (a) Reflection of the light, , (b) Refraction of the light, , (c) Scattering of the light, , (d) Dispersion of the light, , An under water swimmer is at a depth of 12 m below the surface of, water. A bird is at a height of 18 m from the surface of water,, directly above his eyes. For the swimmer the bird appears to be at a, distance from the surface of water equal to (Refractive Index of, water is 4/3), [KCET (Engg.) 2001], , 67., , (a) 24 m, , (b) 12 m, , (c) 18 m, , (d) 9 m, , 75., , (b) 1.36, , (c) 1.42, , (d) 1.46, , Which of the following statement is true, , When light travels from glass to air, the incident angle is 1 and, [Orissa PMT 2004], , The optical path of a monochromatic light is same if it goes through, 4.0 cm of glass or 4.5 cm of water. If the refractive index of glass is, 1.53, the refractive index of the water is, (a) 1.30, , An object is immersed in a fluid. In order that the object becomes, invisible, it should, [AIIMS 2004], (a) Behave as a perfect reflector, (b) Absorb all light falling on it, (c) Have refractive index one, (d) Have refractive index exactly matching with that of the, surrounding fluid, the refracted angle is 2 . The true relation is, , [UPSEAT 2002], , 68., , 74., , (b) 1 2, , (c) 1 2, , (d) Not predictable, , 76., , Velocity of light in a medium is 1.5 10 8 m / s. Its refractive index, will be, [Pb. PET 2000], (a) 8, (b) 6, (c) 4, (d) 2, , 77., , The frequency of a light ray is 6 10 14 Hz. Its frequency when it, propagates in a medium of refractive index 1.5, will be, , [Orissa JEE 2002], , (a) Velocity of light is constant in all media, , (a) 1 2, , (b) Velocity of light in vacuum is maximum, , [MP PMT 2000; DPMT 2003; Pb PMT 2003; MH CET 2004], , (c) Velocity of light is same in all reference frames, , (a) 1.67 10 14 Hz, , (d) Laws of nature have identical form in all reference frames, 69., , A ray of light is incident on a transparent glass slab of refractive, index 1.62. The reflected and the refracted rays are mutually, perpendicular. The angle of incidence is, , (c), 78., , [MP PET 2002], , (a) 58.3, (b) 50, (c) 35, (d) 30, A microscope is focussed on a coin lying at the bottom of a beaker., The microscope is now raised up by 1 cm. To what depth should the, water be poured into the beaker so that coin is again in focus ?, 4, (Refractive index of water is ), 3, o, , o, , o, , 70., , o, , 79., , (a) 1 cm, , 71., , (b), , 8, , 8, , 72., , 73., , (a) 0.64, (c) 1.20, Stars are twinkling due to, , (b) 0.80, (d) 1.44, , (a) Diffraction, , (b) Reflection, , (c) Refraction, , (d) Scattering, , 81., , 82., , A thin oil layer floats on water. A ray of light making an angle of, incidence of 40° shines on oil layer. The angle of refraction of light, ray in water is ( oil 1.45, water 1.33 ), , (c) 26. 8°, , (d) 28.9°, , (b) 0.8, , (c) 1.25, , (d) 1.75, , The wavelength of sodium light in air is 5890 Å. The velocity of, , (a) 5890 Å, , (b) 3681 Å, , (c) 9424 Å, , (d) 15078 Å, , The mean distance of sun from the earth is 1.5 10 8 Km (nearly)., The time taken by the light to reach earth from the sun is, (a) 0.12 min, (b) 8.33 min, (c) 12.5 min, (d) 6.25 min, Refractive index of air is 1.0003. The correct thickness of air column, which will have one more wavelength of yellow light (6000 Å) than, in the same thickness in vacuum is, (a) 2 mm, (b) 2 cm, (c) 2 m, (d) 2 km, The wavelength of light in air and some other medium are, respectively a and m . The refractive index of medium is, [RPMT 2003], , [MP PMT 1993], , (b) 44.5°, , (a) 0.6, , [RPMT 1995], [CPMT 1997], , (a) 36 .1°, , The refractive indices of water and glass with respect to air are 1.2, and 1.5 respectively. The refractive index of glass with respect to, water is, [Pb. PET 2002], , [DCE 2003], , 80., , (d) 4 cm, (c) 3 cm, Velocity of light in glass whose refractive index with respect to air is, 1.5 is 2 10 m/s and in certain liquid the velocity of light found to, be 2.5 10 m/s. The refractive index of the liquid with respect to air, is [CPMT 1978; MP PET/PMT 1988], , (d) 4 10 14 Hz, , light in air is 3 10 8 ms 1 . The wavelength of light in a glass of, refractive index 1.6 would be close to, , [BHU 2003], , 4, cm, 3, , 6 10 14 Hz, , (b) 9.10 10 14 Hz, , 83., , (a), , a / m, , (b) m / a, , (c), , a m, , (d) None of these, , An astronaut in a spaceship see the outer space as, [CPMT 1990, MP PMT 1991; JIPMER 1997], , (a) White, , (b) Black
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84., , (c) Blue, Speed of light is maximum in, , (d) Red, , 85., , (a) Water, (b) Air, (c) Glass, (d) Diamond, Which one of the following statements is correct, , [CPMT 1990; MP PMT 1994; AFMC 1996], , [KCET 1994], , 86., , 5., , [UPSEAT 2001; MP PET 2001], , 6., , (b), , , n, , 90., , [MP PMT 1986], , (a) 49, , 2, , [CPMT 2004; MP PMT 2005], , 89., , o, , (c) 98 o, , Water, , , , 1o, 2, If the critical angle for total internal reflection from a medium to, vacuum is 30°, the velocity of light in the medium is, , (d) 24, 7., , KCET 2000; BCECE 2003; RPMT 2003], , (a), , 3 10 8 m/s, , (b) 1.5 10 8 m/s, , (c) 6 10 8 m/s, (d), 3 10 8 m/s, (a) 2.0, (b) 2.5, 8., A ray of light is incident at an angle i from denser to rare medium., (c) 1.6, (d) 1.5, The reflected and the refracted rays are mutually perpendicular. The, A glass slab of thickness 3 cm and refractive index 3/2 is placed on, angle of reflection and the angle of refraction are respectively r and, ink mark on a piece of paper. For a person looking at the mark at a, r’, then the critical angle will be, distance 5.0 cm above it, the distance of the mark will appear to be [Kerala PMT 2005], CBSE PMT 1996; MP PMT 1985, 99; Pb. PET 2002], (a) 3.0 cm, (b) 4.0 cm, 1, (a) sin (sin r), (c) 4.5 cm, (d) 5.0 cm, A fish at a depth of 12 cm in water is viewed by an observer on the, bank of a lake. To what height the image of the fish is raised., (a) 9 cm, (b) 12 cm, , (b) sin1 (tan r' ), , (c) 3.8 cm, , (d) tan 1 (sin i), , (d) 3 cm, , (c), , sin1 (tan i), , A cut diamond sparkles because of its, (a) Hardness, (b) High refractive index, (c) Emission of light by the diamond, (d) Absorption of light by the diamond, A diver in a swimming pool wants to signal his distress to a person, lying on the edge of the pool by flashing his water proof flash light, (a) He must direct the beam vertically upwards, (b) He has to direct the beam horizontally, (c) He has to direct the beam at an angle to the vertical which is, slightly less than the critical angle of incidence for total internal, reflection, , i r, , [MP PET 2005], , [NCERT 1974; RPET 1996; AFMC 2005], , 2., , Air, , (b) 90 o, , Total Internal Reflection, 1., , [, , an angular range of o where, , , (d) n , n2, In vacuum the speed of light depends upon, [MP PMT 2001], (a) Frequency, (b) Wave length, (c) Velocity of the source of light, (d) None of these, A transparent cube of 15 cm edge contains a small air bubble. Its, apparent depth when viewed through one face is 6 cm and when, viewed through the opposite face is 4 cm. Then the refractive index, of the material of the cube is, , (c), , 88., , 4., , (a) In vacuum, the speed of light depends upon frequency, (b) In vacuum, the speed of light does not depend upon frequency, (c) In vacuum, the speed of light is independent of frequency and, wavelength, (d) In vacuum, the speed of light depends upon wavelength, If the wavelength of light in vacuum be , the wavelength in a, medium of refractive index n will be, (a) n, , 87., , 3., , (d) He has to direct the beam at an angle to the vertical which is, slightly more than the critical angle of incidence for the total, internal reflection, Finger prints on a piece of paper may be detected by sprinkling, fluorescent powder on the paper and then looking it into, (a) Mercury light, (b) Sunlight, (c) Infrared light, (d) Ultraviolet light, Critical angle of light passing from glass to air is minimum for, (a) Red, (b) Green, (c) Yellow, (d) Violet, The wavelength of light in two liquids ‘x' and ‘y' is 3500 Å and, 7000 Å, then the critical angle of x relative to y will be, (a) 60°, (b) 45°, (c) 30°, (d) 15°, A fish is a little away below the surface of a lake. If the critical angle, is 49°, then the fish could see things above the water surface within, , [NCERT 1972], , r1, , [
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9., , 10., , 11., , For total internal reflection to take place, the angle of incidence i, and the refractive index of the medium must satisfy the, inequality, [MP PET 1994], (a), , 1, , sin i, , (b), , (c), , sin i , , (d) sin i , , 18., , 1, , sin i, , Total internal reflection of light is possible when light enters from, (a) Air to glass, , (b) Vacuum to air, , (c) Air to water, , (d) Water to air, , 19., , critical angle, i angle of incidence), [NCERT 1977; MP PMT 1994], , (a) Ray goes from denser medium to rarer medium and i ic, , (c) Ray goes from rarer medium to denser medium and i ic, , 20., , (a) 1.3, (b) 1.4, (c) 1.5, (d) 1.6, When a ray of light emerges from a block of glass, the critical angle, is, [KCET 1994], (a) Equal to the angle of reflection, (b) The angle between the refracted ray and the normal, (c) The angle of incidence for which the refracted ray travels along, the glass-air boundary, (d) The angle of incidence, The phenomenon utilised in an optical fibre is, [KCET 1994; AMU 1995;, , (d) Ray goes from rarer medium to denser medium and i ic, 12., , 13., , CBSE PMT 2001; DCE 1999, 2000, 01, 02; AIEEE 2002], , A diver at a depth of 12m in water ( 4 / 3) sees the sky in a, cone of semi-vertical angle, [KCET 1999; Pb. PMT 2002; MP PMT 1995, 2003], , (a), , sin1 (4 / 3), , (b), , (c), , sin1 (3 / 4 ), , (d) 90°, , 21., , tan 1 (4 / 3), , (a) Refraction, (b) Interference, (c) Polarization, (d) Total internal reflection, The refractive index of water is 4 / 3 and that of glass is 5/3. What, will be the critical angle for the ray of light entering water from the, glass, [RPMT 1996], (a), , Critical angle is that angle of incidence in the denser medium for, which the angle of refraction in rarer medium is, [MP PMT 1996], , 14., , (a) 0°, (b) 57°, (c) 90°, (d) 180°, The critical angle for diamond (refractive index = 2) is, , 15., , (a) About 20°, (b) 60°, (c) 45°, (d) 30°, The reason for shining of air bubble in water is, , [IIT-JEE 1998], , [CPMT 1973; MP PMT 1994], , Total internal reflection of a ray of light is possible when the ( ic =, , (b) Ray goes from denser medium to rarer medium and i ic, , (c) Total internal reflection of light, (d) Diffraction of light, A ray of light travelling in a transparent medium falls on a surface, separating the medium from air at an angle of incidence of 45°. The, ray undergoes total internal reflection. If n is the refractive index of, the medium with respect to air, select the possible value (s) of n, from the following, , sin1, , [RPMT 1999], , [MP PET 2003], , 23., , (a) Air to water, (b) Air to glass, (c) Glass to water, (d) Water to glass, The velocity of light in a medium is half its velocity in air. If ray of, light emerges from such a medium into air, the angle of incidence,, at which it will be totally internally reflected, is, [Roorkee 1999], , (a) 15, (b 30, (c) 45, (d) 60, A ray of light propagates from glass (refractive index = 3/2) to water, (refractive index = 4/3). The value of the critical angle [JIPMER 1999; UPSEAT 20, o, , [MP PET 1997; KCET 1999], , o, , o, , (a) Diffraction of light, , 24., , (b) Dispersion of light, , o, , (c) Scattering of light, (a) sin (1/2), , (d) Total internal reflection of light, 16., , 17., , –1, , With respect to air critical angle in a medium for light of red colour, [1 ] is . Other facts remaining same, critical angle for light of, yellow colour [2 ] will be, , [MP PET 1999], , (a) , , (b) More than , , (c) Less than , , 1, (d), 2, , 25., , 8, , (b) sin1 , 9 , , , , (c) sin1 (8 / 9), (d) sin1 (5 / 7), Relation between critical angles of water and glass is, [CBSE PMT 2000; Pb. PET 2000; CPMT 2001], , 26., , 'Mirage' is a phenomenon due to, [AIIMS 1998; MP PET 2002; AFMC 2003], , (a) Reflection of light, (b) Refraction of light, , 5, 4, , (b) sin1, , 1, 2, (d) sin1, 2, 1, Total internal reflection is possible when light rays travel, , (c), 22., , 4, 5, , sin1, , 27., , (a) C > C, (b) C < C, (c) C = C, (d) C = C = 0, If critical angle for a material to air is 30 , the refractive index of the, material will be, [MP PET 2001], (a) 1.0, (b) 1.5, (c) 2.0, (d) 2.5, The refractive index of water is 1.33. The direction in which a man under, water should look to see the setting sun is, w, , g, , w, , g, , w, , g, , w, , g, , o
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(a) Yellow, orange, red, , [MP PET 1991; Kerala PET 2002; Pb. PET 2003], , (a) 49 to the horizontal, (c) 49 to the vertical, Optical fibres are related with, (a) Communication, (c) Computer, Brilliance of diamond is due to, o, , o, , 28., , 29., , (b) 90 with the vertical, (d) Along the horizontal, o, , (b) Violet, indigo, blue, (c) All colours, , [AFMC 2002], , (d) All colours except green, , (b) Light, (d) None of these, , 36., , iB (iB i A ). Then which of the following is true, , [AIIMS 2002; MP PMT 2003], , 30., , Material A has critical angle i A , and material B has critical angle, (i), , (a) Shape, (b) Cutting, (c) Reflection, (d) Total internal reflection, A light ray from air is incident (as shown in figure) at one end of a, glass fiber (refractive index = 1.5) making an incidence angle of 60, on the lateral surface, so that it undergoes a total internal reflection., How much time would it take to traverse the straight fiber of length, 1 km, , Light can be totally internally reflected when it passes from B, to A, , (ii) Light can be totally internally reflected when it passes from A, to B, , o, , (iii) Critical angle for total internal reflection is iB i A, sin i A, (iv) Critical angle between A and B is sin1 , sin iB, , [Orissa JEE 2002], , (a) 3.33 sec, , Air, , (b) 6.67 sec, , Air, , 60o, , (c) 5.77 sec, 31., , [UPSEAT 2004], , (a) (i) and (iii), (c) (ii) and (iii), , Glass, , (d) 3.85 sec, Light wave enters from medium 1 to medium 2. Its velocity in 2, medium is double from 1 . For total internal reflection the angle of, incidence must be greater than [CPMT 2002], (a) 30, (b) 60, (c) 45, (d) 90, Consider telecommunication through optical fibres. Which of the, following statements is not true, , 37., , nd, , st, , o, , 2 1, 2, , o, , (b, , 3, 2, , (c), , 1, 2, , (d), , 2 1, , [AIEEE 2003], , (a) Optical fibres may have homogeneous core with a suitable, cladding, (b) Optical fibres can be of graded refractive index, (c) Optical fibres are subject to electromagnetic interference from, outside, (d) Optical fibres have extremely low transmission loss, 33., , The critical angle for a medium is 60 o . The refractive index of the, medium is, [MP PMT 2004], (a), , 2, , (b), , 2, 3, , (d), , 3, 2, , 3, , (c), 34., , 38., , 3, , 39., , 35., , 1 , , sin1 , , , , , (b) 90 o, , 1, sin1 2, , , , 1, (d) sin1 , , , , , , , , , , Critical angle for light going from medium (i) to (ii) is . The speed, of light in medium (i) is v then speed in medium (ii) is, (a), , v(1 cos ), , (b, , (c), , v / cos , , (d) v(1 sin ), , v / sin, , If light travels a distance x in t 1 sec in air and 10 x distance in, t 2 sec in a medium, the critical angle of the medium will be, , [MP PMT 2004], , (c), , 45°, Air, , [DCE 2002], , Glass has refractive index with respect to air and the critical angle, for a ray of light going from glass to air is . If a ray of light is, incident from air on the glass with angle of incidence , the, corresponding angle of refraction is, , (a), , (b) (i) and (iv), (d) (ii) and (iv), , In the figure shown, for an angle of incidence 45 o , at the top, surface, what is the minimum refractive index needed for total, internal reflection at vertical face [DCE 2002], (a), , o, , o, , 32., , , , , , , 40., , 41., , White light is incident on the interface of glass and air as shown in, the figure. If green light is just totally internally reflected then the, emerging ray in air contains, [IIT-JEE (Screening) 2004], , Green, , Air, Glass, White, , (a), , t, tan 1 1, t2, , , , , , , (c), , 10 t 1, sin1 , t2, , t , (b) sin1 1 , t2 , , , , , , 10 t 1, (d) tan 1 , t2, , , , , , , The critical angle of a medium with respect to air is 45 o . The, refractive index of medium is, [MH CET 2003], (a) 1.41, , (b) 1.2, , (c) 1.5, , (d) 2, , An endoscope is employed by a physician to view the internal parts, of a body organ. It is based on the principle of, [AIIMS 2004], , (a) Refraction, , (b) Reflection, , (c) Total internal reflection, , (d) Dispersion
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42., , (a), (c), 43., , 45, , o, , (b, , 65, , o, , (d) 43.2 o, , 90, , 90, , o, , (b, , (c) Equal to critical angle, , (a), , f, I, and, 2, 2, , (b), , f and, , I, 4, , (c), , 3f, I, and, 4, 2, , (d), , f and, , 3I, 4, , o, , The phenomena of total internal reflection is seen when angle of, incidence is, [RPMT 2001], (a), , 44., , [CPMT 1989; MP PET 1997; KCET 1998], , A normally incident ray reflected at an angle of 90 o . The value of, critical angle is, [RPMT 1996], , 4., , Greater than critical angle, , A lens of power + 2 diopters is placed in contact with a lens of, power – 1 diopter. The combination will behave like, (a) A convergent lens of focal length 50 cm, , (d) 0 o, , A fish looking up through the water sees the outside world, 4, contained in a circular horizon. If the refractive index of water is, 3, and the fish is 12 cm below the surface, the radius of this circle in, cm is, , (b) A divergent lens of focal length 100 cm, (c) A convergent lens of focal length 100 cm, (d) A convergent lens of focal length 200 cm, 5., , A convex lens of focal length 40 cm is in contact with a concave lens, of focal length 25 cm. The power of combination is, , [NCERT 1980; KCET 2002; AIEEE 2005; CPMT 2005], , 45., , [IIT-JEE 1982; AFMC 1997; CBSE PMT 2000; RPMT 2003], , (a), , 36 5, , (b) 4 5, , (a) – 1.5 D, , (b) – 6.5 D, , (c), , 36 7, , (d) 36 / 7, , (c) + 6.5 D, , (d) + 6.67 D, , A point source of light is placed 4 m below the surface of water of, refractive index 5 / 3. The minimum diameter of a disc which should, be placed over the source on the surface of water to cut–off all light, coming out of water is, , 6., , [NCERT 1981], , [CBSE PMT 1994; JIPMER 2001, 02], , 46., , (a) 2 m, , (b, , (c) 4 m, , (d) 3 m, , 6m, 7., , A fist looking from within water sees the outside world through a, circular horizon. If the fish 7 cm below the surface of water, what, will be the radius of the circular horizon, (a) 3.0 cm, (b) 4.0 cm, (c) 4.5 cm, , The radius of curvature for a convex lens is 40 cm, for each surface., Its refractive index is 1.5. The focal length will be, (a) 40 cm, , (b) 20 cm, , (c) 80 cm, , (d) 30 cm, , A convex lens of focal length f is placed somewhere in between an, object and a screen. The distance between the object and the screen, is x . If the numerical value of the magnification produced by the, lens is m , , then the focal length of the lens is, (a), , (c), 3., , (b) 4.00 D, , (c) –1.00 D, , (d) – 3.75 D, , Two similar plano-convex lenses are combined together in three, different ways as shown in the adjoining figure. The ratio of the, focal lengths in three cases will be, , (d) 5.0 cm, , [MP PMT 1989], , 2., , (a) 1.66 D, , [Kerala PMT 2005], , Refraction at Curved Surface, 1., , Two lenses are placed in contact with each other and the focal, length of combination is 80 cm. If the focal length of one is 20 cm,, then the power of the other will be, , mx, (m 1)2, , (b), , (m 1)2, x, m, , (d), , 8., , (b, , 1:1:1, , (c) 1 : 2 : 2, , (d) 2 : 1 : 1, , Two lenses of power +12 and – 2 diopters are placed in contact., What will the focal length of combination, [MP PET 1990; MNR 1987;, MH CET (Med.) 2001; UPSEAT 2000; Pb. PMT 2003], , 9., , mx, (m 1)2, , (a) 10 cm, , (b) 12.5 cm, , (c) 16.6 cm, , (d) 8.33 cm, , A concave and convex lens have the same focal length of 20 cm and, are put into contact to form a lens combination. The combination is, used to view an object of 5 cm length kept at 20 cm from the lens, combination. As compared to the object, the image will be, (a) Magnified and inverted, , (m 1)2, x, m, , (b) Reduced and erect, , A thin lens focal length f1 and its aperture has diameter d. It forms, an image of intensity I. Now the central part of the aperture upto, d, diameter, is blocked by an opaque paper. The focal length and, 2, image intensity will change to, , (a) 2 : 2 : 1, , (c) Of the same size as the object and erect, (d) Of the same size as the object but inverted, 10., , If in a plano-convex lens, the radius of curvature of the convex surface is, 10 cm and the focal length of the lens is 30 cm, then the refractive index, of the material of lens will be, , [
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[CPMT 1986; MNR 1988; MP PMT 2002; UPSEAT 2000], , 11., , (a) 1.5, , (b) 1.66, , (c) 1.33, , (d) 3, , [CPMT 1974, 77; MP PMT 1992], , 19., , The slit of a collimator is illuminated by a source as shown in the, adjoining figures. The distance between the slit S and the collimating, lens L is equal to the focal length of the lens. The correct direction, of the emergent beam will be as shown in figure, 1, , 2, , 3, , 20., , S, , 12., , L, , S, , L, , S, , L, , (a) 1, , (b) 3, , (c) 2, , (d) None of the figures, , (c), 21., , A converging lens is used to form an image on a screen. When, upper half of the lens is covered by an opaque screen, , (a) Half the image will disappear, (b) Complete image will be formed of same intensity, (c) Half image will be formed of same intensity, (d) Complete image will be formed of decreased intensity, A thin convex lens of focal length 10 cm is placed in contact with a, concave lens of same material and of same focal length. The focal, length of combination will be, [CPMT 1972; 1988], , 14., , 15., , 16., , (a) Zero, (b) Infinity, (c) 10 cm, (d) 20 cm, A convex lens of focal length 84 cm is in contact with a concave lens, of focal length 12 cm. The power of combination (in diopters) is, (a) 25/24, (b) 25/18, (d) + 50/7, (c) – 50/7, A convex lens makes a real image 4 cm long on a screen. When the, lens is shifted to a new position without disturbing the object, we, again get a real image on the screen which is 16 cm tall. The length, of the object must be, [MP PET 1991], (a) 1/4 cm, (b) 8 cm, (c) 12 cm, (d) 20 cm, , 22., , 23., , 24., , 25., , 26., , [BHU 1994; MP PMT 1996], , 27., , (a) If n1 n2 ng, , (c) If n1 n2 and n1 ng, 18., , n1, , I1 I2, , (b), (d), , I1 I2, , I1 / I2, , A convex lens of crown glass ( n =1.525) will behave as a divergent, lens if immersed in, [CPMT 1984], (a) Water (n =1.33), (b) In a medium of n = 1.525, (c) Carbon disulphide n =1.66, (d) It cannot act as a divergent lens, A divergent lens will produce, [CPMT 1984], (a) Always a virtual image, (b) Always real image, (c) Sometimes real and sometimes virtual, (d) None of the above, The minimum distance between an object and its real image formed, by a convex lens is, [CPMT 1973; JIPMER 1997], (a) 1.5 f, , (b) 2 f, , (c) 2.5 f, , (d) 4 f, , An object is placed at a distance of 20 cm from a convex lens of, focal length 10 cm. The image is formed on the other side of the lens, at a distance, [CPMT 1971; RPET 2003], (a) 20 cm, (b) 10 cm, (c) 40 cm, (d) 30 cm, Two thin lenses, one of focal length + 60 cm and the other of focal, length – 20 cm are put in contact. The combined focal length is [CPMT 1973, 89, (a) + 15 cm, (b) – 15 cm, (c) + 30 cm, (d) –30 cm, A double convex lens of focal length 20 cm is made of glass of, refractive index 3 / 2. When placed completely in water, (a w 4 / 3) , its focal length will be, [CBSE PMT 1990; MP PMT/PET 1998], , (a) 2 m, (b) 4 cm, (c) 16 cm, (d) 32 cm, The ray diagram could be correct, [CPMT 1988], (b) If n1 n2 and n1 ng, , I1 / I2, , [MP PET 1991], , A glass convex lens ( g 1.5) has a focal length of 8 cm when, placed in air. What would be the focal length of the lens when it is, immersed in water ( w 1.33 ), , 17., , If I1 and I2 be the size of the images respectively for the two, positions of lens in the displacement method, then the size of the, object is given by, [CPMT 1988], (a), , [IIT-JEE 1986; SCRA 1994;, MP PET 1996; MP PMT 2004; BHU 1998, 05], , 13., , (a) 15 cm, (b) 10 cm, (c) 30 cm, (d) 60 cm, A glass lens is placed in a medium in which it is found to behave, like a glass plate. Refractive index of the medium will be, (a) Greater than the refractive index of glass, (b) Smaller than the refractive index of glass, [CPMT, 1986], (c) Equal, to refractive, index of glass, (d) No case will be possible from above, , (a) 80 cm, (b) 15 cm, (c) 17.7 cm, (d) 22.5 cm, Two thin lenses of focal lengths 20 cm and 25 cm are placed in, contact convex. The effective power of the combination is, [CBSE PMT 1990; RPMT 2001], , ng, , (a) 45 dioptres, (c) 1/9 dioptre, , n2, , Lens, (d) Under no circumstances, A thin convex lens of refractive index 1.5 has a focal length of 15 cm, in air. When the lens is placed in liquid of refractive index 4/3 , its, focal length will be, , 28., , (b) 9 dioptres, (d) 6 dioptres, , An object is placed at a distance of f / 2 from a convex lens. The, image will be, [CPMT 1974, 89], (a) At one of the foci, virtual and double its size
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29., , (b) At 3f / 2, real and inverted, (c) At 2f, virtual and erect, (d) None of these, A double convex thin lens made of glass (refractive index = 1.5), has both radii of curvature of magnitude 20 cm. Incident light rays, parallel to the axis of the lens will converge at a distance L such that, , 38., , [MNR 1991; MP PET 1996; UPSEAT 2000; Pb PET 2004], , 30., , (a) L = 20 cm, (b) L = 10 cm, (c) L = 40 cm, (d) L = 20 / 3 cm, A lens behaves as a converging lens in air and a diverging lens in, water. The refractive index of the material is, , 39., , (b) 2 concave lenses, (c) 1 convex lens and 1 concave lens, (d) Convex lens and plane mirror, A plano convex lens ( f 20cm) is silvered at plane surface. Now f, will be, [BHU 1995; DPMT 2001; MP PMT 2005], (a) 20 cm, (b) 40 cm, (c) 30 cm, (d) 10 cm, If the central portion of a convex lens is wrapped in black paper as, shown in the figure, [Manipal MEE 1995; KCET 2001], , [CPMT 1991; NCERT 1979; BHU 2005], , 31., , (a) Equal to unity, (b) Equal to 1.33, (c) Between unity and 1.33, (d) Greater than 1.33, A biconvex lens forms a real image of an object placed perpendicular, to its principal axis. Suppose the radii of curvature of the lens tend, to infinity. Then the image would, , (a), (b), (c), (d), , [MP PET 1994], , 32., , (a) Disappear, (b) Remain as real image still, (c) Be virtual and of the same size as the object, (d) Suffer from aberrations, The radius of curvature of convex surface of a thin plano-convex, lens is 15 cm and refractive index of its material is 1.6. The power of, the lens will be, [MP PMT 1994], (a) 1 D, (b) 2 D, (c), , 33., , 3D, , (d) 4 D, , 40., , 41., , Focal length of a convex lens will be maximum for, , [AFMC 1995], , [MP PMT 1994], , 34., , (a) Blue light, (b) Yellow light, (c) Green light, (d) Red light, A lens is placed between a source of light and a wall. It forms, images of area A1 and A2 on the wall for its two different, positions. The area of the source or light is, , 42., , [CBSE PMT 1995], , (a), , A1 A2, 2, , (b), , 1, 1 , , , , A, A, 2, 1, , 1, , No image will be formed by the remaining portion of the lens, The full image will be formed but it will be less bright, The central portion of the image will be missing, There will be two images each produced by one of the exposed, portions of the lens, A diminished image of an object is to be obtained on a screen 1.0 m, from it. This can be achieved by appropriately placing, (a) A convex mirror of suitable focal length, (b) A concave mirror of suitable focal length, (c) A concave lens of suitable focal length, (d) A convex lens of suitable focal length less than 0.25 m, The focal length of convex lens is 30 cm and the size of image is, quarter of the object, then the object distance is, , 43., , (a) 150 cm, (b) 60 cm, (c) 30 cm, (d) 40 cm, A convex lens forms a real image of a point object placed on its, principal axis. If the upper half of the lens is painted black, the, image will, [MP PET 1995], (a) Be shifted downwards, (b) Be shifted upwards, (c) Not be shifted, (d) Shift on the principal axis, In the figure, an air lens of radii of curvature 10 cm ( R1 = R 2 =, 10 cm) is cut in a cylinder of glass ( 1.5) . The focal length and, the nature of the lens is, , 2, , 35., , A A2 , , A1 A2, (c), (d) 1, 2, , , Two lenses of power 6D and – 2D are combined to form a single, lens. The focal length of this lens will be, , [MP PET 1995; Pb. PET 2000], , Air, , Glass, , [MP PET 2003], , (a), , 3, m, 2, , (c) 4 m, 36., , (d), , 1, m, 8, , A combination of two thin lenses with focal lengths f1 and f2, respectively forms an image of distant object at distance 60 cm, when lenses are in contact. The position of this image shifts by 30, cm towards the combination when two lenses are separated by 10, cm. The corresponding values of f1 and f2 are, (a), , 37., , (b, , 1, m, 4, , 30 cm, 60 cm, , (b), , 20 cm , 30 cm, , (c) 15 cm, 20 cm, (d) 12 cm, 15 cm, An achromatic combination of lenses is formed by joining, [BHU 1995; Pb. PMT 2000, 04], , (a) 2 convex lenses, , 44., , 45., , (a) 15 cm, concave, (b) 15 cm, convex, (c) , neither concave nor convex, (d) 0, concave, A lens (focal length 50 cm) forms the image of a distant object, which subtends an angle of 1 milliradian at the lens. What is the size, of the image, [MP PMT 1995], (a) 5 mm, , (b) 1 mm, , (c) 0.5[AIIMS, mm 1995], , (d) 0.1 mm, , A convex lens of focal length 12 cm is made of glass of , What will be its focal length when immersed in liquid of , (a) 6 cm, , (b) 12 cm, , 5, 4, , 3, ., 2
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(c) 24 cm, 46., , (d) 30 cm, , (c) 0.75 cm, (d) 0.5 cm, A, symmetric, double, convex, lens, is, cut in two equal parts by a plane, Two thin lenses of focal lengths f1 and f2 are in contact and, perpendicular to the principal axis. If the power of the original lens, coaxial. The combination is equivalent to a single lens of power [MP PET 1996, 98;, was 4 D, the power of a cut lens will be, 55., , MP PMT 1998; DCE 2000; UP SEAT 2005], , 47., , 48., , (a), , f1 f2, , (b), , f1 f2, f1 f2, , (c), , 1, ( f1 f2 ), 2, , (d), , f1 f2, f1 f2, , [MP PMT 1999], , 56., , (a) R/ 2, , (b) R, (d) 1.5 R, , 57., , Two lenses have focal lengths f1 and f2 and their dispersive, powers are 1 and 2 respectively. They will together form an, achromatic combination if, , 49., , 50., , (a) 1 f1 2 f2, , (b) 1 f2 2 f1 0, , (c) 1 f1 2 f2, , (d) 1 f1 2 f2, 58., , (c) Convex, 25 cm, , 59., , A thin double convex lens has radii of curvature each of magnitude, 40 cm and is made of glass with refractive index 1.65. Its focal, length is nearly, [MP PMT 1997], (a) 20 cm, (b) 31 cm, (c) 35 cm, , 51., , (d) 50 cm, , 60., , The plane surface of a plano-convex lens of focal length f is silvered., It will behave as, [MP PMT/PET 1998], (a) Plane mirror, (b) Convex mirror of focal length 2 f, , 61., , (c) Concave mirror of focal length f / 2, (d) None of the above, 52., , An equiconvex lens of glass of focal length 0.1 metre is cut along a, plane perpendicular to principle axis into two equal parts. The ratio, of focal length of new lenses formed is, , 62., , [MP PET 1999; DPMT 2000], , 53., , 54., , (a) 1 : 1, , (b) 1 : 2, , (c) 2 : 1, , 1, (d) 2 :, 2, , A lens of refractive index n is put in a liquid of refractive index n', of focal length of lens in air is f , its focal length in liquid will be, (a), , , , fn' (n 1), n'n, , (b) , , (c), , , , n' (n 1), f (n'n), , (d), , An object of height 1.5 cm is placed on the axis of a convex lens of, focal length 25 cm. A real image is formed at a distance of 75 cm, from the lens. The size of the image will be, (a) 4.5 cm, (b) 3.0 cm, , cm 2003], (b) 100 cm, (a) 50[RPET, (c) 200 cm, (d) 400 cm, A concave lens of glass, refractive index 1.5, has both surfaces of, same radius of curvature R. On immersion in a medium of refractive, index 1.75, it will behave as a, (a) Convergent lens of focal length 3.5 R, (b) Convergent lens of focal length 3.0 R, (c) Divergent lens of focal length 3.5 R, (d) Divergent lens of focal length 3.0 R, A convex lens of focal length 0.5 m and concave lens of focal length, 1 m are combined. The power of the resulting lens will be, (a) 1 D[MP PET 1997], (b) – 1 D, (c) 0.5 D, (d) – 0.5 D, A double convex lens is made of glass of refractive index 1.5. If its, focal length is 30 cm, then radius of curvature of each of its curved, surface is, [Bihar CEET 1995], (a) 10 cm, (b) 15 cm, (c) 18 cm, (d) None of these, A thin lens made of glass of refractive index 1.5 has a front surface +, 11 D power and back surface – 6 D. If this lens is submerged in a, liquid of refractive index 1.6, the resulting power of the lens is, (a) – 0.5 D, (b) + 0.5 D, (c) – 0.625 D, (d) + 0.625 D, An object is placed first at infinity and then at 20 cm from the, object side focal plane of the convex lens. The two images thus, formed are 5 cm apart. The focal length of the lens is, (a) 5 cm, (b 10 cm, (c) 15 cm, (d) 20 cm, The distance between an object and the screen is 100 cm. A lens, produces an image on the screen when placed at either of the, positions 40 cm apart. The power of the lens is, [SCRA 1994], , 63., , f (n'n), n' (n 1), , fn' n, n n', , [CBSE PMT 1999;, , [IIT-JEE 1999], , The dispersive powers of glasses of lenses used in an achromatic, pair are in the ratio 5 : 3. If the focal length of the concave lens is 15, cm, then the nature and focal length of the other lens would be, (b) Concave, 9 cm, (a) Convex, 9 cm, (d) Concave, 25 cm, , (b) 3 D, (d) 5 D, refractive index 1.6. The radius of, is 60 cm. The focal length of the, , Pb. PMT 1999; BHU 2001; Very Similar to BHU 2003], , A plano convex lens is made of glass of refractive index 1.5. The, radius of curvature of its convex surface is R. Its focal length is, (c) 2R, , (a) 2 D, (c) 4 D, A plane convex lens is made of, curvature of the curved surface, lens is, , 64., , (a) 3 dioptres, (b) 5 dioptres, (c) 7 diopters, (d) 9 diopters, The image distance of an object placed 10 cm in front of a thin lens, of focal[MP, length, 5 cm is, [SCRA 1994], PET+1999], (a) 6.5 cm, (b) 8.0 cm, (c) 9.5 cm, (d) 10.0 cm, A achromatic combination is made with a lens of focal length f and, dispersive power with a lens having dispersive power of 2 ., The focal length of second will be, [RPET 1997], , (a) 2 f, (c), , f / 2, , [MP PET 1999], , (b), , f /2, , (d) – 2 f, , [
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65., , 66., , 67., , A biconvex lens with equal radii curvature has refractive index 1.6, and focal length 10 cm. Its radius of curvature will be, (a) 20 cm, (b) 16 cm, (c) 10 cm, (d) 12 cm, A convex lens, [RPMT 1997], (a) Converges light rays, (b) Diverges light rays, (c) Form real images always, (d) Always forms virtual images, The focal length of a combination of lenses formed with lenses, having powers of + 2.50 D and – 3.75 D will be, , 75., , 76., , 69., , 70., , (a) R, (b) 2R, (d) R / 2, (c) 4R, Focal length of a convex lens of refractive index 1.5 is 2 cm. Focal, length of lens when immersed in a liquid of refractive index of 1.25, will be, [CBSE PMT 1993], (a) 10 cm, (b) 2.5 cm, (c) 5 cm, (d) 7.5 cm, The focal length of a convex lens depends upon, , (c), , (n 1) f, , [MP PET 2003], , f, n, , (b), , (d) (n 1) f, , Two thin lenses whose powers are +2D and –4D respectively combine,, then the power of combination is, (a) – 2D, , (b) + 2D, , (c) – 4D, , (d) + 4D, , A substance is behaving as convex lens in air and concave in water,, then its refractive index is, [BHU 1998], (a) Smaller than air, , (a) – 20 cm, (b) – 40 cm, (d) – 80 cm, (c) – 60 cm, Focal length of a converging lens in air is R. If it is dipped in water, of refractive index 1.33, then its focal length will be around, (Refractive index of lens material is 1.5), [RPMT 1997; EAMCET (Med.) 1995], , nf, , [AFMC 1998; CPMT 1996; Very Similar to BHU 2004], , [RPMT 1997], , 68., , (a), , (b) Greater than both air and water, (c) Greater than air but less than water, (d) Almost equal to water, 77., , A concave lens of focal length 20 cm placed in contact with a plane, mirror acts as a, [SCRA 1998], (a) Convex mirror of focal length 10 cm, (b) Concave mirror of focal length 40 cm, (c) Concave mirror of focal length 60 cm, (d) Concave mirror of focal length 10 cm, , 78., , [AFMC 1994], , (a) Frequency of the light ray, (b) Wavelength of the light ray, , A convex lens is used to form real image of an object on a screen. It, is observed that even when the positions of the object and that, screen are fixed there are two positions of the lens to form real, images. If the heights of the images are 4 cm and 9 cm respectively,, the height of the object is, , (c) Both (a) and (b), 71., , 72., , [AMU (Med.) 1999], , (d) None of these, , (a) 2.25 cm, , (b, , If a convex lens of focal length 80 cm and a concave lens of focal, length 50 cm are combined together, what will be their resulting, power, [CBSE PMT 1996; AFMC 2002], , (c) 6.50 cm, , (d) 36.00 cm, , (a) + 6.5D, , (b) – 6.5 D, , (c) + 7.5 D, , (d) – 0.75 D, , fv and fr are the focal lengths of a convex lens for violet and red, , light respectively and Fv and Fr are the focal lengths of a concave, lens for violet and red light respectively, then, , 73., , 79., , (a), , fv fr and Fv Fr, , (b, , fv fR and Fv Fr, , (c), , fc fr and Fv Fr, , (d), , fv fr and Fv Fr, , If a lens is cut into two pieces perpendicular to the principal axis, and only one part is used, the intensity of the image, , 80., , 81., , 74., , (c) 2 times, , (d) Infinite, , 1, times than, A convex lens of focal length f produces an image, n, that of the size of the object. The distance of the object from the, lens is, [BHU 1997; JIPMER 2001, 02], , (a) Concave, 25 cm, , (b) Convex, 50 cm, , (c) Concave, 20 cm, , (d) Convex, 100 cm, , A double convex lens, glass1996], of = 1.5 has radius of curvature of, [CBSEofPMT, each of its surface is 0.2 m. The power of the lens is, (a) + 10 dioptres, , (b) – 10 dioptres, , (c) – 5 dioptres, , (d) +5 dioptres, , A lens of focal power 0.5 D is, , [JIPMER 1999], , (b) A concave lens of focal length 0.5 m, , 1, times, 2, , (b), , A convex lens of power + 6D is placed in contact with a concave, lens of power – 4D. What is the nature and focal length of the, combination, [AMU (Engg.) 1999], , (a) A convex lens of focal length 0.5 m, , [CPMT 1996], , (a) Remains same, , 6.00 cm, , (c) A convex lens of focal length 2 m, (d) A concave lens of focal length 2 m, 82., , A lens which has focal length of 4 cm and refractive index of 1.4 is, immersed in a liquid of refractive index 1.6, then the focal length will, be, [RPMT 1999], (a) – 12.8 cm, , (b) 32 cm, , (c) 12.8 cm, , (d) – 32 cm
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83., , 84., , 85., , A convex lens has 9 cm focal length and a concave lens has – 18 cm, focal length. The focal length of the combination in contact will be, (a) 9 cm, , (b) – 18 cm, , (c) – 9 cm, , (d) 18 cm, , 91., , [MP PMT 2000], , A double convex thin lens made of glass of refractive index 1.6 has, radii of curvature 15 cm each. The focal length of this lens when, immersed in a liquid of refractive index 1.63 is, (a) – 407 cm, , (b) 250 cm, , (c) 125 cm, , (d) 25 cm, , (a) 7.5 cm, (b) 15.0 cm, (c) 75 cm, (d) 5.0 cm, 92. [UPSEAT, A convex, has 2004], a focal length f. It is cut into two parts along the, 2000;lens, Pb. PET, dotted line as shown in the figure. The focal length of each part will, be, [MP PET 2000], (a), , A lens of power + 2 diopters is placed in contact with a lens of, power – 1 diopoter. The combination will behave like, , 93., , (c) A convergent lens of focal length 100 cm, (d) A divergent lens of focal length 100 cm, Chromatic aberration of lens can be corrected by, [AFMC 2000], , 94., , (a) Reducing its aperature, (b) Proper polishing of its two surfaces, (c) Suitably combining it with another lens, (d) Providing different suitable curvature to its two surfaces, 87., , The relation between n and n , if behaviour of light rays is as shown, in figure is, [KCET 2000], 1, , (a), , n1 n 2, , (b, , n 2 n1, , (c), , n1 n 2, , 95., , 2, , [KCET 2000, 01], , n1, , n2, , 96., , (d) n1 n 2, 88., , Lens, , A candle placed 25 cm from a lens, forms an image on a screen, placed 75 cm on the other end of the lens. The focal length and, type of the lens should be, [KCET 2000], , 97., , (a) + 18.75 cm and convex lens, (b) – 18.75 cm and concave lens, 98., , (c) + 20.25 cm and convex lens, (d) – 20.25 cm and concave lens, 89., , We combined a convex lens of focal length f and concave lens of, focal lengths f and their combined focal length was F. The, combination of these lenses will behave like a concave lens, if, 1, , 2, , (a) f > f, , (b) f < f, , (c) f = f, , (d) f f, , 1, , 1, , 90., , 2, , 2, , 3, f, 2, (d) 2f, An object has image thrice of its original size when kept at 8 cm, and 16 cm from a convex lens. Focal length of the lens is, (a) 8 cm, (b) 16 cm, (c) Between 8 cm and 16 cm, (d) Less than 8 cm, The combination of a convex lens (f = 18 cm) and a thin concave, lens (f = 9 cm) is, [AMU (Engg.) 2001], (a) A concave lens (f = 18 cm), (b) A convex lens (f = 18 cm), (c) A convex lens (f = 6 cm), (d) A concave lens (f = 6 cm), A convex lens forms a real image of an object for its two different, positions on a screen. If height of the image in both the cases be 8, cm and 2 cm, then height of the object is, , (c), , (a) A divergent lens of focal length 50 cm, (b) A convergent lens of focal length 50 cm, , f, 2, , (b) f, , [UPSEAT 2000], , 86., , The focal length of a convex lens is 10 cm and its refractive index is, 1.5. If the, [RPMT, radius, 1999], of curvature of one surface is 7.5 cm, the radius of, curvature of the second surface will be, , 1, , 2, , 1, , 99., , 2, , In a plano-convex lens the radius of curvature of the convex lens is, 10 cm. If the plane side is polished, then the focal length will be, (Refractive index = 1.5), [CBSE PMT 2000; BHU 2004], , (a) 10.5 cm, , (b, , 10 cm, , (c) 5.5 cm, , (d) 5 cm, 100., , (a) 16 cm, (b) 8 cm, (c) 4 cm, (d) 2 cm, A convex lens of focal length 25 cm and a concave lens of focal, length 10 cm are joined together. The power of the combination will, be, [MP PMT 2001], (a) – 16 D, (b) + 16 D, (c) – 6 D, (d) + 6 D, The unit of focal power of a lens is, [KCET 2001], (a) Watt, (b) Horse power, (c) Dioptre, (d) Lux, A thin lens made of glass of refractive index = 1.5 has a focal, length equal to 12 cm in air. It is now immersed in water, 4, , [UPSEAT 2002], . Its new focal length is, 3, , (a) 48 [KCET, cm 2000], (b) 36 cm, (c) 24 cm, (d) 12 cm, Figure given below shows a beam of light converging at point P., When a convex lens of focal length 16 cm is introduced in the path, of the beam at a place O shown by dotted line such that OP, becomes the axis of the lens, the beam converges at a distance x, from the lens. The value x will be equal to, (a) 12 cm, (b) 24 cm, P, (c) 36 cm, O, (d) 48 cm, 12cm apart, the, If two + 5 D lenses are mounted at some distance, cm cm, equivalent power will always be negative if the distance is
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[UPSEAT 2002], , 101., , (a) Greater than 40 cm, , (b) Equal to 40 cm, , (c) Equal to 10 cm, , (d) Less than 10 cm, , A convex lens is dipped in a liquid whose refractive index is equal to, the refractive index of the lens. Then its focal length will, (a) Become infinite, (b) Become small, but non–zero, (c) Remain unchanged, (d) Become zero, , 109., , An equiconvex lens is cut into two halves along (i) XOX and (ii), YOY as shown in the figure. Let f, f , f be the focal lengths of, the complete lens, of each half in case (i), and of each half in case, (ii), respectively, , A convex lens produces a real image m times the size of the object., What will be the distance of the object from the lens, [JIPMER 2002], , 102., , 108., , (a), , m 1, , f, m , , (b) (m –1)f, , (c), , m 1, , f, m , , (d), , m 1, f, , Y, , A convex lens is made up of three different materials as shown in, the figure. For a point object placed on its axis, the number of, images formed are, [KCET 2002], , X, , X, , O, , (a) 1, (b) 5, , Y the following, Choose the correct statement from, , (c) 4, , [CBSE PMT 2003], , (d) 3, 103., , 104., , 105., , An object is placed 12 cm to the left of a converging lens of focal, length 8 cm. Another converging lens of 6 cm focal length is placed, at a distance of 30 cm to the right of the first lens. The second lens, will produce, [KCET 2002], (a) No image, , (b) A virtual enlarged image, , (c) A real enlarged image, , (d) A real smaller image, , If convex lens of focal length 80cm and a concave lens of focal, length 50 cm are combined together, what will be their resulting, power, [AFMC 2002], (a) + 6.5 D, , (b) – 6.5 D, , (c) + 7.5 D, , (d) – 0.75 D, , A point object O is placed in front of a glass rod having spherical, end of radius of curvature 30 cm. The image would be formed at, , 110., , 111., , O Air, , (c) 1 cm to the right, , 112., , Glass, 30 cm, , 15 cm, , 113., , (d) 18 cm to the left, 106., , 107., , The focal length of lens of refractive index 1.5 in air is 30 cm. When, 4, it is immersed in a liquid of refractive index, , then its focal, 3, length in liquid will be, [BHU 2002], (a) 30 cm, , (b) 60 cm, , (c) 120 cm, , (d) 240 cm, , 114., , f1 f2, f1 f2, , (b), , f1 f2, f1 f2, , (c), , 2 f1 f2, f1 f2, , (d), , 2 f1 f2, f1 f2, , f f , f f, , (c), , f 2 f , f 2 f, , (d), , f f , f 2 f, , The sun makes 0.5 angle on earth surface. Its image is made by, convex lens of 50 cm focal length. The diameter of the image will, be, [CPMT 2003], (a) 5 mm, (b) 4.36 mm, (c) 7 mm, (d) None of these, The chromatic Aberration in lenses becomes due to, o, , (a) Disimilarity of main axis of rays, (b) Disimilarity of radii of curvature, (c) Variation of focal length of lenses with wavelength, (d) None of these, If aperture of lens is halved then image will be, [AFMC 2003], [Orissa JEE 2002], (a) No effect on size, (b) Intensity of image decreases, (c) Both (a) and (b), (d) None of these, When the convergent nature of a convex lens will be less as, compared with air, [AFMC 2003], (a) In water, (b) In oil, (c) In both (a) and (b), (d) None of these, An achromatic combination of lenses produces, [KCET 1993; JIPMER 1997], , 2, , (a), , (b), , (a), (b), (c), (d), , Two thin lenses of focal lengths f and f are in contact. The focal, length of this combination is, [MP PET 2002], 1, , f 2 f , f f, , [CPMT 2003], , (a) 30 cm left, (b) Infinity, , (a), , 115., , Coloured images, Highly enlarged image, Images in black and white, Images unaffected by variation of refractive index with, wavelength, In a parallel beam of white light is incident on a converging lens, the, colour which is brought to focus nearest to the lens is, (a) Violet, (b) Red, (c) The mean colour, (d) All the colours together
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116., , 117., , A magnifying glass is to be used at the fixed object distance of 1, inch. If it is to produce an erect image magnified 5 times its focal, length should be, [MP PMT 1990], (a) 0.2 inch, (b) 0.8 inch, (d) 5 inch, (c) 1.25 inch, A film projector magnifies a 100 cm film strip on a screen. If the, linear magnification is 4, the area of magnified film on the screen is, 2, , 125., , 126., , CPMT 1977, 91; MP PET 1985, 89; RPMT 2001; BCEC 2005], , (a) 1600 cm, (b) 400 cm, (c) 800 cm, (d) 200 cm, An object placed 10 cm in front of a lens has an image 20 cm behind, the lens. What is the power of the lens (in dioptres), 2, , 2, , 2, , 118., , 2, , 127., , [MP PMT 1995], , 119., , 120., , (a) 1.5, (b) 3.0, (c) – 15.0, (d) + 15.0, A beam of parallel rays is brought to a focus by a plano-convex lens., A thin concave lens of the same focal length is joined to the first, lens. The effect of this is, [KCET 2004], (a) The focal point shifts away from the lens by a small distance, (b) The focus remains undisturbed, (c) The focus shifts to infinity, (d) The focal point shifts towards the lens by a small distance, A thin plano-convex lens acts like a concave mirror of focal length, 0.2 m when silvered from its plane surface. The refractive index of, the material of the lens is 1.5. The radius of curvature of the convex, surface of the lens will be, , 128., , 129., , 121., , 122., , 123., , 124., , (c) – 50 cm, , (d) – 30 cm, , (b) 30 cm, , (c) 60 cm, , (d) 80 cm, , (c) 40 cm, , (d) 15 cm, , (b) 200 cm, , (c) 100 cm, , (d) 50 cm, , The radius of the convex surface of plano-convex lens is 20 cm and, the refractive index of the material of the lens is 1.5. The focal length, of the lens is, [CPMT 2004], (a) 30 cm, , (b) 50 cm, , (c) 20 cm, , (d) 40 cm, , A combination of two thin convex lenses of focal length 0.3 m and, 0.1 m will have minimum spherical and chromatic aberrations if the, distance between them is, [UPSEE 2004], (a) 0.1 m, , (b, , (c) 0.3 m, , (d) 0.4 m, , 0.2 m, , A bi-convex lens made of glass (refractive index 1.5) is put in a liquid, of refractive index 1.7. Its focal length will, , Increase and change sign, , (c) Decrease and remain of the same sign, (d) Increase and remain of the same sign, 130., , Spherical aberration in a lens, , [UPSEAT 2004], , (a) Is minimum when most of the deviation is at the first surface, (b) Is minimum when most of the deviation is at the second, surface, , (d) Does not depend on the above consideration, 131., , 132., , 133., , The focal lengths of convex lens for red and blue light are 100 cm, and 96.8 cm respectively. The dispersive power of material of lens is, (a) 0.325, , (b, , 0.0325, , (c) 0.98, , (d) 0.968, , The power of an achromatic convergent lens of two lenses is + 2 D., The power of convex lens is + 5D. The ratio of dispersive power of, convex and concave lens will be, (a) 5 : 3, , (b, , 3:5, , (c) 2 : 5, , (d) 5 : 2, , The focal lengths for violet, green and red light rays are fV , fG and, , f R respectively. Which of the following is the true relationship [BHU 2004; CBS, , [Orssia PMT 2004], , (b, , (a) 400 cm, , [Pb. PET 2003], , A double convex lens (R1 R 2 10 cm) ( 1.5) having focal, length equal to the focal length of a concave mirror. The radius of, curvature of the concave mirror is, (a) 10 cm, , A plano-convex lens is made of refractive index of 1.6. The radius of, curvature, of the curved surface is 60 cm. The focal length of the, [NCERT 1980;, lens is, [Pb. PET 2000], , [Pb. PET 2003], , A plano-convex lens of refractive index 1.5 and radius of curvature, 30 cm is silvered at the curved surface. Now this lens has been used, to form the image of an object. At what distance from this lens an, object be placed in order to have a real image of the size of the, object, [AIEEE 2004], (a) 20 cm, , (d) 90 cm, , (c) Is minimum when the total deviation is equally distributed over, the two surface, , In order to obtain a real image of magnification 2 using a, converging lens of focal length 20 cm, where should an object be, placed, [AFMC 2004], (b) 30 cm, , (c) 15 cm, , (b, , (b) 4 cm, (d) 12 cm, , (a) 50 cm, , (b) 60 cm, , [UPSEAT 2004], , [IIT-JEE (Screening) 2004], , (a) 2 cm, (c) 6 cm, , (a) 30 cm, , (a) Decrease and change sign, , [KCET 2004], , (b 0.2 m, (a) 0.4 m, (c) 0.1 m, (d) 0.75 m, A point object is placed at the center of a glass sphere of radius 6, cm and refractive index 1.5. The distance of the virtual image from, the surface of the sphere is, , At what distance from a convex lens of focal length 30 cm, an object, should be placed so that the size of the image be 1/2 of the object, , 20 cm, 134., , (a), , fR fG fV, , (b, , fV fG fR, , (c), , fG fR fV, , (d), , fG fV fR, , Two lenses of power + 12 and – 2 diopters are placed in contact. The, combined focal length of the combination will be
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135., , (a) 8.33 cm, , (b) 1.66 cm, , (c) 12.5 cm, , (d) 10 cm, , 144., , When light rays from the sun fall on a convex lens along a direction, parallel to its axis, [MP PMT 2004], , A thin equiconvex lens is made of glass of refractive index 1.5 and its, focal length is 0.2 m, if it acts as a concave lens of 0.5 m focal, length when dipped in a liquid, the refractive index of the liquid is, (a), , (a) Focal length for all colours is the same, (b, , 145., , (d) Focal length for red colour is the shortest, , 137., , 138., , A convex lens is in contact with concave lens. The magnitude of the, ratio of their focal length is 2/3. Their equivalent focal length is 30, cm. What are their individual focal lengths, (a) – 75, 50, , (b) – 10, 15, , (c) 75, 50, , (d) – 15, 10, , (b) – 25 D, , (c) 1 D, , (d) None of these, , 140., , 1., , 2., , The plane faces of two identical plano-convex lenses each having, focal length of 40 cm are pressed against each other to form a usual, convex lens. The distance from this lens, at which an object must be, placed to obtain a real, inverted image with magnification one is, (a) 80 cm, (b 40 cm, (d) 162 cm, (c) 20 cm, If two lenses of +5 diopters are mounted at some distance apart, the, equivalent power will always be negative if the distance is, (a) Greater than 40 cm, (b) Equal to 40 cm, (c) Equal to 10 cm, (d) Less than 10 cm, A concave lens and a convex lens have same focal length of 20 cm, and both put in contact this combination is used to view an object 5, cm long kept at 20 cm from the lens combination. As compared to, object the image will be, (a) Magnified and inverted, (b Reduced and erect, (c) Of the same size and erect, (d) Of the same size and inverted, The focal length of the field lens (which is an achromatic, combination of two lenses) of telescope is 90 cm. The dispersive, powers of the two lenses in the combination are 0.024 and 0.036., The focal lengths of two lenses are, , 3., , 4., , [CPMT 2005], , 142., , (a) 30 cm and 60 cm, (b 30 cm and – 45 cm, (c) 45 cm and 90 cm, (d) 15 cm and 45 cm, A combination of two thin lenses of the same material with focal, lengths f1 and f2 , arranged on a common axis minimizes, chromatic aberration, if the distance between them is, ( f1 f2 ), ( f1 f2 ), (a), (b), 4, 2, (c), , 143., , ( f1 f2 ), , (d), , 2( f1 f2 ), , If the focal length of a double convex lens for red light is fR , its, focal length for the violet light is, [EAMCET 2005], (a) fR, (b) Greater than fR, (c) Less than fR, , (d), , 2 fR, , Which source is associated with a line emission spectrum, [MP PET/PMT 1988; CBSE PMT 1993], , [CPMT 2005], , 141., , 13, 9, (d), 8, 8, The dispersive power of the material of lens of focal length 20 cm is, 0.08. The longitudinal chromatic aberration of the lens is, (a) 0.08 cm, (b) 0.08/20 cm, (d) 0.16 cm, (c) 1.6 cm, [IIT-JEE (Screening) 2005], , [NCERT 1980; CPMT 1981; MP PMT 1999; UPSEAT 1999], , 139., , 15, 8, , Prism Theory & Dispersion of Light, , A thin glass (refractive index 1.5) lens has optical power of 5 D in, air. It's optical power in a liquid medium with refractive index 1.6, will be, [AIEEE 2005], (a) 25 D, , (b), , (c), , Focal length for violet colour is the shortest, , (c) Focal length for yellow colour is the longest, 136., , 17, 8, , 5., , (a) Electric fire, , (b) Neon street sign, , (c) Red traffic light, , (d) Sun, , Formula for dispersive power is (where symbols have their usual, meanings), [MP PMT/PET 1988], or, If the refractive indices of crown glass for red, yellow and violet, colours are respectively r , y and v , then the dispersive power, of this glass would be, [MP PMT 1996], (a), , v y, r 1, , (b), , v r, y 1, , (c), , [BCECE, v y 2005], y r, , (d), , v r, 1, y, , The critical angle between an equilateral prism and air is 45°. If the, incident ray is perpendicular to the refracting surface, then, (a) After deviation it will emerge from the second refracting, surface, (b) It is totally reflected on the second surface and emerges out, perpendicularly from third surface in air, (c) It is totally reflected from the second and third refracting, surfaces and finally emerges out from the first surface, (d) It is totally reflected from all the three sides of prism and never, emerges out, When white light passes through a glass prism, one gets spectrum, on the other side of the prism. In the emergent beam, the ray which, is deviating least is or, Deviation by a prism is lowest for, [MP PMT 1997], (a) Violet ray, (b) Green ray, (c) Red ray, (d) Yellow ray, We use flint glass prism to disperse polychromatic light because, light of different colours, [EAMCET 2005], , [MP PET 1993], , (a) Travel with same speed, (b) Travel with same speed but deviate differently due to the shape, of the prism, (c) Have different anisotropic properties while travelling through, the prism, (d) Travel with different speeds
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6., , 7., , 8., , A prism ( 1.5) has the refracting angle of 30°. The deviation of, a monochromatic ray incident normally on its one surface will be, (sin 48° 36’ = 0.75), , [MNR 1998; MP PMT 1989, 92, 2002; CPMT 1993, 2004], , [CPMT 1973; MP PMT 1989; MP PMT 2004], , (a) 30°, (b) 45°, (c) 60°, (d) 75°, The ratio of angle of minimum deviation of a prism in air and when, dipped in water will be ( a g 3 / 2 and a w 4 / 3 ), , (b) 20° 30’, , (c) 18°, , (d) 22°1’, 17., , Fraunhofer lines are obtained in, (a) Solar spectrum, (b) The spectrum obtained from neon lamp, (c) Spectrum from a discharge tube, (d) None of the above, When light rays are incident on a prism at an angle of 45°, the, minimum deviation is obtained. If refractive index of the material of, , 18., , (a) 30°, (c) 50°, , (b) 40°, (d) 60°, , A spectrum is formed by a prism of dispersive power ' ' . If the, angle of deviation is ' ' , then the angular dispersion is, , 19., , 12., , (a) / , , (b) / , , (c) 1/ , , (d) , , 20., , Light from sodium lamp is passed through cold sodium vapours, the, spectrum of transmitted light consists of, (a) A line at 5890 Å, (b) A line at 5896 Å, (c) Sodium doublet lines, (d) No spectral features, Angle of minimum deviation for a prism of refractive index 1.5 is, equal to the angle of prism. The angle of prism is (cos 41° = 0.75), (a) 62°, (b) 41°, (c) 82°, (d) 31°, In the formation of primary rainbow, the sunlight rays emerge at, minimum deviation from rain-drop after, , 21., , 14., , (a) One internal reflection and one refraction, (b) One internal reflection and two refractions, (c) Two internal reflections and one refraction, (d) Two internal reflections and two refractions, Dispersive power depends upon, [RPMT 1997], (a) The shape of prism, (b) Material of prism, (c) Angle of prism, (d) Height of the prism, When white light passes through the achromatic combination of, prisms, then what is observed, (a) Only deviation, (c) Deviation and dispersion, , (b) Only dispersion, (d) None of the above, , The dispersion for a medium of wavelength is D, then the, dispersion for the wavelength 2 will be, [MP PET 1989], , (a) D/8, (c) D/2, , (b) D/4, (d) D, , ( y 1), , (a), , , , (c), , (y '1), , ( y '1), , (b), , ( y '1), ( y 1), , (d) (y 1), , The number of wavelengths in the visible spectrum, (a) 4000, , (b) 6000, , (c) 2000, , (d) Infinite, , The black lines in the solar spectrum during solar eclipse can be, explained by, [MP PMT 1989], (a) Planck's law, , (b) Kirchoff's law, , (c) Boltzmann's law, , (d) Solar disturbances, , The dispersive power is maximum for the material, [MP PET/PMT 1988], , (c) Mixture of both, 22., , 23., , 24., , [MP PMT 1989], , 15., , (d) 1/4, , The respective angles of the flint and crown glass prisms are A’ and, A. They are to be used for dispersion without deviation, then the, ratio of their angles A' /A will be, , (a) Flint glass, , [MP PET 1989], , 13., , (c) 3/4, , [MP PMT 1989], , [MP PET 1989; RPMT 2001], , 11., , (b) 1/2, , [MP PMT 1989], , [MP PMT 1989], , 10., , (a) 1/8, , 2 , then the angle of prism will be, [MP PMT 1986], , 9., , The refractive index of a prism for a monochromatic wave is 2, and its refracting angle is 60°. For minimum deviation, the angle of, incidence will be, , [MP PMT/PET 1988], , (a) 18° 36’, , prism is, , 16., , 25., , (b) Crown glass, (d) None of the above, , A light ray is incident by grazing one of the face of a prism and, after refraction ray does not emerge out, what should be the angle, of prism while critical angle is C, (a) Equal to 2C, , (b) Less than 2C, , (c) More than 2C, , (d) None of the above, , A parallel beam of monochromatic light is incident at one surface of, a equilateral prism. Angle of incidence is 55° and angle of emergence, is 46°. The angle of minimum deviation will be, (a) Less than 41°, , (b) Equal to 41°, , (c) More than 41°, , (d) None of the above, , The spectrum of light emitted by a glowing solid is, (a) Continuous spectrum, , (b) Line spectrum, , (c) Band spectrum, , (d) Absorption spectrum, , Light rays from a source are incident on a glass prism of index of, refraction and angle of prism . At near normal incidence, the, angle of deviation of the emerging rays is, [MP PMT 1993], , (a) ( 2), (c), , ( 1), , (b) ( 1), (d) ( 2)
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26., , 27., , 28., , (a) Less than the emergent angle, , Which of the following element was discovered by study of, Fraunhofer lines, (a) Hydrogen, , (b) Oxygen, , (c) Helium, , (d) Ozone, , By placing the prism in minimum deviation position, images of the, spectrum, (a) Becomes inverted, , (b) Becomes broader, , (c) Becomes distinct, , (d) Becomes intensive, , (b) Greater than the emergent angle, (c) Sum of angle of incidence and emergent angle is 90°, (d) Equal to the emergent angle, 36., , Our eye is most sensitive for which of the following wavelength, (a) 4500 Å, 37., , (b) 5500 Å, , 29., , 30., , 31., , 32., , (c) White, , (d) Violet, , The fine powder of a coloured glass is seen as, (b) White, , (d) Equally sensitive for all wave lengths of visible spectrum, , (c) That of the glass colour, , (d) Black, , Three prisms of crown glass, each have angle of prism 9° and two, prisms of flint glass are used to make direct vision spectroscope., What will be the angle of flint glass prisms if for flint is 1.60 and, for crown glass is 1.53, (a) 11.9°, , (b) 16.0°, , (c) 15.3°, , (d) 9.11°, , 38., , When a white light passes through a hollow prism, then, [MP PMT 1987], , (a) There is no dispersion and no deviation, (b) Dispersion but no deviation, (c) Deviation but no dispersion, , If the refractive indices of crown glass for red, yellow and violet, colours are 1.5140, 1.5170 and 1.5318 respectively and for flint glass, these are 1.6434, 1.6499 and 1.6852 respectively, then the dispersive, powers for crown and flint glass are respectively, , (d) There is dispersion and deviation both, 39., , (a) 0.034 and 0.064, , (b) 0.064 and 0.034, , The light ray is incidence at angle of 60° on a prism of angle 45°., When the light ray falls on the other surface at 90°, the refractive, [MPmaterial, PET/PMTof1988], index of the, prism and the angle of deviation are, given by, [DPMT 2001], , (c) 1.00 and 0.064, , (d) 0.034 and 1.0, , (a), , 2 , 30 o, , (c), , , , (b) 1.5 , 15 o, , The minimum temperature of a body at which it emits light is, (a) 1200°C, , (b) 1000°C, , (c) 500°C, , (d) 200°C, , Band spectrum is obtained when the source emitting light is in the, form of or, , 40., , (a) Atoms, , (b, , (c) Plasma, , (d) None of the above, , (a) 12°2.4', , (b) 12°4’, , (c) 1.24°, , (d) 12°, , (c) 50°, , (d) 100°, , In the position of minimum deviation when a ray of yellow light, passes through the prism, then its angle of incidence is, [MP PMT 1989; RPMT 1997], , In dispersion without deviation, , (d) All the rays are parallel, but not parallel to the incident ray, 41., , Deviation of 5° is observed from a prism whose angle is small and, whose refractive index is 1.5. The angle of prism is, (a) 7.5°, , (b) 10°, , (c) 5°, , (d) 3.3°, , [DPMT 2001], , The angle of minimum deviation for a prism is 40° and the angle of, the prism is 60°. The angle of incidence in this position will be, (b) 60°, , 3, , 15 o, 2, , (c) Only red coloured ray is parallel to the incident ray, , 42., , (a) 30°, , (d) , , (b) Yellow coloured ray is parallel to the incident ray, , Molecules, , Flint glass prism is joined by a crown glass prism to produce, dispersion without deviation. The refractive indices of these for, mean rays are 1.602 and 1.500 respectively. Angle of prism of flint, prism is 10°, then the angle of prism for crown prism will be, , 3, , 30 o, 2, , (a) The emergent rays of all the colours are parallel to the incident, ray, , [EAMCET (Engg.) 1995; MH CET 1999; CPMT 2000], , 35., , (b) Brown, , (a) Coloured, , [CPMT 1988; MP PET 1994; DCE 2004; MP PET 2005], , 34., , (a) Green, , (c) 6500 Å, , Band spectrum is characteristic of, , 33., , A circular disc of which 2/3 part is coated with yellow and 1/3 part is, with blue. It is rotated about its central axis with high velocity, then, it will be seen as, , 43., , The refractive indices of violet and red light are 1.54 and 1.52, respectively. If the angle of prism is 10°, then the angular dispersion, is, [MP PMT 1990], (a) 0.02, , (b) 0.2, , (c) 3.06, , (d) 30.6, , The angle of minimum deviation measured with a prism is 30° and, the angle of prism is 60°. The refractive index of prism material is, (a), , 2, , (c) 3/2, , (b) 2, (d) 4/3, , [
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44., , If the refractive indices of a prism for red, yellow and violet colours, be 1.61, 1.63 and 1.65 respectively, then the dispersive power of the, prism will be, , (c) H, 52., , [MP PET 1991; DPMT 1999], , 45., , (a), , 1 .65 1 .62, 1 .61 1, , (b), , 1 .62 1 .61, 1 .65 1, , (c), , 1 .65 1 .61, 1 .63 1, , (d), , 1 .65 1 .63, 1 .61 1, , 53., , The minimum deviation produced by a hollow prism filled with a, certain liquid is found to be 30°. The light ray is also found to be, refracted at angle of 30°. The refractive index of the liquid is, (a), , 2, , (c), , 3, 2, , (b), , 54., , (d) Na, , 2, , The band spectra (characteristic of molecular species) is due to, emission of radiation, [CPMT 1982, 90], (a) Gaseous state, , (b) Liquid state, , (c) Solid state, , (d) All of three states, , Line spectrum was first of all theoretically explained by, (a) Swan, , (b) Fraunhofer, , (c) Kirchoff, , (d) Bohr, , The spectrum of iodine gas under white light will be, (a) Only violet, [MP PET, (b) Bright, lines1991], , (c) Only red lines, , 3, , (d) Some black bands in continuous spectrum, , 46., , (d), , 3, 2, , 55., , Minimum deviation is observed with a prism having angle of prism, , A, angle of deviation , angle of incidence i and angle of emergence, e. We then have generally, , 56., , (c) Kerosene oil lamp flame, , (d) Candle flame, , Fraunhofer lines are produced by, (b) The elements present in the chromosphere of the sun, , (a) i > e, , (b) i < e, , (c) i = e, , (d) i = e = , , (c) The vapour of the element present in the chromosphere of the, sun, , A thin prism P with angle 4° and made from glass of refractive, index 1.54 is combined with another thin prism P made from glass, of refractive index 1.72 to produce dispersion without deviation. The, angle of prism P is, , (d) The carbon dioxide present in the atmosphere, , 1, , 2, , 57., , [MP PMT 1991, 92; IIT-JEE 1990; MP PET 1995, 99;, , (b) 3°, , (c) 4°, , (d) 5.33°, , (c) Light is gradually bent rather than sharply refracted at an, interface between the medium and air, , An achromatic prism is made by combining two prisms, P1 (v 1.523, r 1.515) and P2 (v 1.666, r 1.650) ;, where represents the refractive index. If the angle of the prism, , (d) Light is never totally internally reflected, 58., , P1 is 10°, then the angle of the prism P will be, 2, , A ray of light is incident at an angle of 60° on one face of a prism of, angle 30°. The ray emerging out of the prism makes an angle of 30°, with the incident ray. The emergent ray is, [EAMCET 1990; MP PMT 1990], , [MP PMT 1991], , 49., , (a) 5°, , (b) 7.8°, , (a) Normal to the face through which it emerges, , (c) 10.6°, , (d) 20°, , (b) Inclined at 30° to the face through which it emerges, , Angle of a prism is 30° and its refractive index is 2 and one of, the surface is silvered. At what angle of incidence, a ray should be, incident on one surface so that after reflection from the silvered, surface, it retraces its path, , (c) Inclined at 60° to the face through which it emerges, (d) None of these, 59., , [MP PMT 1991; UPSEAT 2001; CBSE PMT 2004], , 50., , 51., , [MP PMT 1990], , (b) Light of different wavelengths propagate at same speed but has, different frequencies, , UPSEAT 2001; RPMT 2004], , (a) 2.6°, , A medium is said to be dispersive, if, , (a) Light of different wavelengths propagate at different speeds, , 2, , 48., , (b) Electric bulb, , (a) The element present in the photosphere of sun, , [MP PET 1991], , 47., , Continuous spectrum is not due to, (a) Hydrogen flame, , (a) 30°, , (b) 60°, , (c) 45°, , (d) sin1 1.5, , of refraction r will be correct, [MP PMT 1990], , For a material, the refractive indices for red, violet and yellow colour, light are respectively 1.52, 1.64 and 1.60. The dispersive power of the, material is, [MP PMT 1991], (a) 2, , (b) 0.45, , (c) 0.2, , (d) 0.045, , Band spectrum is produced by, (a) H, , In a thin prism of glass (refractive index 1.5), which of the following, relations between the angle of minimum deviations m and angle, , 60., , (a), , m r, , (b) m 1.5 r, , (c), , m 2r, , (d) m , , r, 2, , The figures represent three cases of a ray passing through a prism, of angle A. The case corresponding to minimum deviation is, , [CPMT 1978], , (b) He, , (1), , (2), , (3)
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3, , (b), , 2, , 61., , (c), , (a) 1, , (b) 2, , (c) 3, , (d) None of these, , Dispersion can take place for, , [MP PET 1992], , (b) Longitudinal waves only but not for transverse waves, , A light ray is incident upon a prism in minimum deviation position, and suffers a deviation of 34°. If the shaded half of the prism is, knocked off, the ray will, [MP PMT 1992], , (c) Both transverse and longitudinal waves, , (a) Suffer a deviation of 34°, , (d) Neither transverse nor longitudinal waves, , (b) Suffer a deviation of 68°, , Emission spectrum of CO 2 gas, (b, , 68., , (c) Suffer a deviation of 17°, , [MP PET 1992], , (d) Not come out of the prism, , (a) Is a line spectrum, , 69., , Is a band spectrum, , (c) Is a continuous spectrum, (d) Does not fall in the visible region, 63., , (a) 45°, , (b) 39°, , (c) 20°, , (d) 30°, , The true statement is, (a) The order of colours in the primary and the secondary, rainbows is the same, , 66., , (a) Black, , (b) Blue, , (c) Orange, , (d) Red, , (b) 45°, , (c) 60°, , (d) 0°, , Three glass prisms A, B and C of same refractive index are placed in, contact with each other as shown in figure, with no air gap between, the prisms. Monochromatic ray of light OP passes through the, prism assembly and emerges as QR. The conditions of minimum, deviation is satisfied in the prisms, (a) A and C, , (c) The intensity of light in the primary rainbow is greater and the, order of colours is the same than the secondary rainbow, , What will be the colour of sky as seen from the earth, if there were, no atmosphere, [MP PMT 1992], , (a) 30°, , [CPMT 1988], , (b) The intensity of colours in the primary and the secondary, rainbows is the same, , 65., , 2 , the angle of incidence on the first face, [EAMCET 1983], , 70., , (d) The intensity of light for different colours in primary rainbow, is greater and the order of colours is reverse than the, secondary rainbow, , A ray of monochromatic light is incident on one refracting face of a, prism of angle 75°. It passes through the prism and is incident on, the other face at the critical angle. If the refractive index of the, material of the prism is, of the prism is, , A ray of light passes through an equilateral glass prism in such a, manner that the angle of incidence is equal to the angle of, emergence and each of these angles is equal to 3/4 of the angle of, the prism. The angle of deviation is, [MNR 1988; MP PMT 1999; Roorkee 2000; UPSEAT 2000; MP PET 2005], , 64., , 4, 3, , (d), , (a) Transverse waves only but not for longitudinal waves, , 62., , 2, , P, , (b) B and C, , B, A, , (c) A and B, , C, , (d) In all prisms A, B and C, 71., , Q, , O, , The refractive index of a material of a prism of angles 45°– 45°R –, 90° is 1.5. The path of the ray of light incident normally on the, hypotenuse side is shown in, [EAMCET 1985], , A, , A, , (a), , When light emitted by a white hot solid is passed through a sodium, flame, the spectrum of the emergent light will show, , (b), , 90°, , 90°, , [MP PMT 1992], , B, , (a) The D1 and D2 bright yellow lines of sodium, , 45°, , B, , C, , (d), , (d) No colours at all, 67., , A prism ABC of angle 30° has its face AC silvered. A ray of light, incident at an angle of 45° at the face AB retraces its path after, refraction at face AB and reflection at face AC. The refractive index, of the material of the prism is, [MP PMT 1992; EAMCET 2001], , (a) 1.5, , A, , 45°, , B, , Silvered, , C, , B, , 72., , 45°, , C, , 90°, , 90°, , (c) All colours from violet to red, , 45°, , 45°, , A, , A, , (c), , (b) Two dark lines in the yellow region, , 45°, , 45°, , C, , B, , 45°, , 45°, , C, , At the time of total solar eclipse, the spectrum of solar radiation, would be, [MP PMT 1990; RPMT 2004], (a) A large number of dark Fraunhofer lines, (b) A less number of dark Fraunhofer lines, (c) No lines at all, (d) All Fraunhofer lines changed into brilliant colours
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73., , Angle of deviation ( ) by a prism (refractive index = and, supposing the angle of prism A to be small) can be given by, (a), , 74., , ( 1) A, , 81., , (b) ( 1) A, , A , sin, 1, 2, (d) , (c) , A, A, , 1, sin, 2, Angle of prism is A and its one surface is silvered. Light rays falling, at an angle of incidence 2A on first surface return back through the, same path after suffering reflection at second silvered surface., Refractive index of the material of prism is, (a) 2 sin A, (b) 2 cos A, 1, (d) tan A, cos A, 2, A ray of light incident normally on an isosceles right angled prism, travels as shown in the figure. The least value of the refractive index, of the prism must be, , [MP PMT 1995; Pb. PMT 2001; RPMT 2003], , 82., , 2, , (b), , 3, , (b) 45°, , (c) 60°, , (d) 90°, , When light of wavelength is incident on an equilateral prism, kept in its minimum deviation position, it is found that the angle of, deviation equals the angle of the prism itself. The refractive index of, the material, the prism for the wavelength is, then, [AIIMSof1995], , 3, , (c) 2, 83., , [Manipal MEE 1995; BHU 2003], , (a), , (a) 30°, , (a), , (c), 75., , A ray passes through a prism of angle 60° in minimum deviation, position[MPand, PMTsuffers, 1994] a deviation of 30°. What is the angle of, incidence on the prism, , 78., , 79., , (a), , V, , (b), , V, , R, , 90°, , C, , B, , [MP PET 1995], , 80., , 2, , [NSEP 1994; MP PET 1996], , When seen in green light, the saffron and green portions of our, National Flag will appear to be [Manipal MEE 1995], (a) Black, (b) Black and green respectively, (c) Green, (d) Green and yellow respectively, At sun rise or sunset, the sun looks more red than at mid-day, because, [AFMC 1995; Similar to DCE 2003], (a) The sun is hottest at these times, (b) Of the scattering of light, (c) Of the effects of refraction, (d) Of the effects of diffraction, Line spectrum contains information about, [MP PET 1995], (a) The atoms of the prism, (b) The atoms of the source, (c) The molecules of the source, (d) The atoms as well as molecules of the source, Missing lines in a continuous spectrum reveal, (a), (b), (c), (d), , (d), , A, , (d) 2.0, , 77., , 3, 2, , Which of the following diagrams, shows correctly the dispersion of, white light by a prism, , (c) 1.5, 76., , (b), , Defects of the observing instrument, Absence of some elements in the light source, Presence in the light source of hot vapours of some elements, Presence of cool vapours of some elements around the light, source, , R, , (c), , 84., , V, R, , A neon sign does not produce, [MP PET 1996; UPSEAT 2004], , (a) Line spectrum, (b) An emission spectrum, (c) An absorption spectrum, (d) Photons, 85., , 86., , The refractive index of flint glass for blue F line is 1.6333 and red C, line is 1.6161. If the refractive index for yellow D line is 1.622, the, dispersive power of the glass is, (a) 0.0276, , (b) 0.276, , (c) 2.76, , (d) 0.106, , A triangular prism of glass is shown in the figure. A ray incident, normally to one face is totally reflected, if 45 o . The index of, refraction of glass is, [AIEEE 2004], (a) Less than 1.41, (b) Equal to 1.41, , A source emits light of wavelength 4700Å, 5400 Å and 6500 Å. The, light passes through red glass before being tested by a spectrometer., Which wavelength is seen in the spectrum, [MP PMT 1995], , (d), R, V, , , , (c) Greater than 1.41, (d) None of the above, 87., , 45o, , (a) 6500 Å, , (b) 5400 Å, , The wavelength of emission line spectrum and absorption line, spectrum of a substance are related as, , (c) 4700 Å, , (d) All the above, , (a) Absorption has larger value, (b) Absorption has smaller value
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97., , (d) No relation, , For a medium, refractive indices for violet, red and yellow are 1.62,, 1.52 and 1.55 respectively, then dispersive power of medium will be, , White light is passed through a prism whose angle is 5°. If the, refractive indices for rays of red and blue colour are respectively, 1.64 and 1.66, the angle of deviation between the two colours will be, , (a) 0.65, , (b) 0.22, , (c) 0.18, [MP PET 1997], , (d) 0.02, , (c) They are equal, 88., , 89., , [RPET 1997], , (a) 0.1 degree, , (b) 0.2 degree, , (c) 0.3 degree, , (d) 0.4 degree, , 98., , From which source a continuous emission spectrum and a line, absorption spectrum are simultaneously obtained, [MP PMT 1997], , (a), (b), (c), (d), 90., , Bunsen burner flame, The sun, Tube light, Hot filament of an electric bulb, , 99., , 100., , A thin prism P1 with angle 6° and made from glass of refractive, index 1.54 is combined with another thin prism P of refractive index, 1.72 to produce dispersion without deviation. The angle of prism, [MP PMT 1999], P2 will be, 2, , 91., , 93., , 94., , (a) 2 : 3, , (b) 3 : 2, , (c) 4 : 9, , (d) 9 : 4, , If refractive index of red, violet and yellow lights are 1.42, 1.62 and, 1.50 respectively for a medium. Its dispersive power will be, (a) 0.4, , (b) 0.3, , (c) 0.2, , (d) 0.1, , A ray is incident at an angle of incidence i on one surface of a prism, of small angle A and emerges normally from the opposite surface. If, the refractive index of the material of the prism is , the angle of, incidence i is nearly equal to, [CBSE PMT 1992], , (a) 5° 24’, , (b) 4° 30’, , (a) A / , , (c) 6°, , (d) 8°, , (c), , If the refractive index of a material of equilateral prism is, angle of minimum deviation of the prism is, , 3 , then, , 101., , (b), , (d) A / 2, , A, , Fraunhofer spectrum is a, , [KCET 1993, 94; RPET 1997;, , (a) Line absorption spectrum, , (a) 30°, , (b) 45°, , (b) Band absorption spectrum, , (c) 60°, , (d) 75°, , (c) Line emission spectrum, , The splitting of white light into several colours on passing through a, glass prism is due to, [CPMT 1999], (a) Refraction, , (b) Reflection, , (c) Interference, , (d) Diffraction, , (d) Band emission spectrum, 102., , A white screen illuminated by green and red light appears to be, (a) Green, , (b) Red, , (c) Yellow, , (d) White, , 103., , The angle of a prism is 60° and its refractive index is 2 . The, angle of minimum deviation suffered by a ray of light in passing, through it is, [MP PET 2003], [KCET 1994; RPMT 1997], (a) About, 20°, , (b) 30°, , (c) 60°, , (d) 45°, , Colour of the sky is blue due to, , Dark lines on solar spectrum are due to, , [CPMT 1996, 99; AFMC 1993; AIIMS 1999;, [EAMCET (Engg.) 1995], , AIEEE 2002; BCECE 2003; BHU 2004], , (a) Lack of certain elements, (b) Black body radiation, (c) Absorption of certain wavelengths by outer layers, (d) Scattering, 95., , Line spectra are due to, , A / 2, , MP PET 1997, 2001; JIPMER 2000; AIIMS 2001], , [CBSE PMT 1999; Pb. PMT 2004; MH CET 2004], , 92., , Two lenses having f1 : f2 2 : 3 has combination to make no, dispersion. Find the ratio of dispersive power of glasses used, , 104., , [EAMCET (Med.) 1995], , (a) Hot solids, (b) Atoms in gaseous state, , 105., , (a) Scattering of light, , (b) Total internal reflection, , (c) Total emission, , (d) None of the above, , Which of the following spectrum have all the frequencies from high, to low frequency range, [CPMT 1996], (a) Band spectrum, , (b) Continuous spectrum, , (c) Line spectrum, , (d) Discontinuous spectrum, , Stars are not visible in the day time because, , (c) Molecules in gaseous state, 96., , [JIPMER 1997], , (d) Liquid at low temperature, , (a) Stars hide behind the sun, , The path of a refracted ray of light in a prism is parallel to the base, of the prism only when the, [SCRA 1994], , (b) Stars do not reflect sun rays during day, (c) Stars vanish during the day, , (a) Light is of a particular wavelength, , (d) Atmosphere scatters sunlight into a blanket of extreme, brightness through which faint stars cannot be visible, , (b) Ray is incident normally at one face, (c) Ray undergoes minimum deviation, (d) Prism is made of a particular type of glass, , 106., , Which of the following colours suffers maximum deviation in a, prism, [KCET 1998; DPMT 2000]
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107., , (a) Yellow, , (b) Blue, , (c) Green, , (d) Orange, , 116., , If a thin prism of glass is dipped into water then minimum deviation, (with respect to air) of light produced by prism will be left, , When a ray of light is incident normally on one refracting surface of, an equilateral prism (Refractive index of the material of the prism =, 1.5, [EAMCET (Med.) 2000], (a) Emerging ray is deviated by 30, (b) Emerging ray is deviated by 45, (c) Emerging ray just grazes the second refracting surface, (d) The ray undergoes total internal reflection at the second, refracting surface, Consider the following two statements A and B and identify the, correct choice in the given answers, o, , o, , 3, 4, , a g and a w , 2, 3, , , 108., , [UPSEAT 1999], , (a), , 1, 2, , (b), , 1, 4, , (c), , 2, , (d), , 1, 5, , 117., , [EAMCET (Engg.) 2000], , A:, B:, (a), (b), (c), (d), , The refractive indices for the light of violet and red colours of any, material are 1.66 and 1.64 respectively. If the angle of prism made, of this material is 10 , then angular dispersion will be, o, , (a) 0.20, , (c) 0.40, 109., , 110., , (b) 0.10, , o, , o, , (d) 1, , o, , o, , The refractive index of the material of the prism for violet colour is, 1.69 and that for red is 1.65. If the refractive index for mean colour, is 1.66, the dispersive power of the material of the prism, (a) 0.66, , (b) 0.06, , (c) 0.65, , (d) 0.69, o, , o, , (a) 0, , 112., , (a) 0.268, (b) 0.368, (c) 0.468, (d) 0.568, Dispersion of light is due to, [DCE 1999], (a) Wavelength, (b) Intensity of light, (c) Density of medium, (d) None of these, A prism of refracting angle 60 is made with a material of refractive, index . For a certain wavelength of light, the angle of minimum, deviation is 30 . For this, wavelength the value of refractive index of, the material is, , o, , (c) 45, , o, , 119., , [KCET (Engg.) 1999], , 111., , Under minimum deviation condition in a prism, if a ray is incident, at an angle 30 , the angle between the emergent ray and the second, [JIPMER, 1999], refracting, surface, of the prism is, [EAMCET (Engg.) 2000], , The deviation caused in red, yellow and violet colours for crown, glass prism are 2.84 , 3.28 and 3.72 respectively. The dispersive, power of prism material is, o, , 118., , Line spectra is due to atoms in gaseous state, Band spectra is due to molecules, Both A and B are false, 1999], A [UPSEAT, is true and, B is false, A is false and B is true, Both A and B are true, , o, , (d) 60, , o, , The angle of prism is 5 and its refractive indices for red and violet, colours are 1.5 and 1.6 respectively. The angular dispersion, produced by the prism is, [MP PMT 2000], o, , (a) 7.75, (c) 0.5, 120., , (b) 30, , o, , o, , o, , (b) 5, , o, , (d) 0.17, , o, , If the refractive angles of two prisms made of crown glass are 10, and 20 respectively, then the ratio of their colour deviation powers, will be, , o, , o, , o, , [KCET 1999; AFMC 2001], , o, , [CPMT 1999, MH CET 2000], , 113., , (a) 1.231, (b) 1.820, (c) 1.503, (d) 1.414, Which of the prism is used to see infrared spectrum of light, , 121., , 114., , 115., , (c) 4 : 1, , (d) 1 : 2, , The nature of sun’s spectrum is, , (a) Continuous spectrum with absorption lines, , Nicol, Crown, gets split into its constituent, , (b) Line spectrum, (c) The spectrum of the helium atom, , [DCE 2000], , (b) Because is different for different , (c) Diffraction of light, (d) Velocity changes for different frequencies, The dispersive powers of crown and flint glasses are 0.02 and 0.04, respectively. In an achromatic combination of lenses the focal length, of flint glass lens is 40 cm. The focal length of crown glass lens will, be, [DCE 2000], (a) – 20 cm, (b) + 20 cm, (c) – 10 cm, (d) + 10 cm, , (b) 2 : 1, , [MP PET 2000; MP PMT 2001], , [RPMT 2000], , (a) Rock Salt, (b), (c) Flint, (d), When white light enters a prism, it, colours. This is due to, (a) High density of prism material, , (a) 1 : 1, , (d) Band spectrum, 122., , A ray of light is incident normally on one of the face of a prism of, angle 30 and refractive index, o, , 2 . The angle of deviation will be, [KCET 2001], , 123., , o, , (a) 26, , (b) 0, , (c) 23, , o, , (d) 15, , o, , o, , For a prism of refractive index 1.732, the angle of minimum, deviation is equal to the angle of the prism. The angle of the prism, is, [CBSE PMT 2001], (a) 80, , o, , (b) 70, , o
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(c) 60, 124., , 125., , (d) 50, , o, , o, , The spectrum obtained from an electric lamp or red hot heater is, (a) Line spectrum, , (b) Band spectrum, , (c) Absorption spectrum, , (d) Continuous spectrum, , When a glass prism of refracting angle 60 is immersed in a liquid its, angle of minimum deviation is 30 . The critical angle of glass with respect, to the liquid medium is, [EAMCET 2001], , (c) Dispersion and total internal reflection, (d)2001;None, of these, [BHU, Pb. PET, 2003], 133. The Cauchy’s dispersion formula is, [AIIMS 2002], , o, , o, , 126., , (a) 42, , o, , (b) 45, , o, , (c) 50, , o, , (d) 52, , o, , 134., , (b) n A B2 C4, , (c), , n A B2 C4, , (d) n A B2 C4, , A prism of refractive index and angle A is placed in the minimum, deviation position. If the angle of minimum deviation is A, then the, value of A in terms of is, [EAMCET 2003], , Three prisms 1, 2 and 3 have the prism angle A = 60 , but their, refractive indices are respectively 1.4, 1.5 and 1.6. If , , be their, respective angles of deviation then, 2, , (a), , , sin1 , 2, , (b) sin1, , (c), , , 2 cos 1 , 2, , , (d) cos 1 , 2, , 3, , [MP PMT 2001], , (a) > > , 3, , 2, , (b) > > , , 1, , 1, , (c) = = , 1, , 2, , 2, , 135., , (d) > > , , 3, , 2, , 1, , 1, , 2, , 3, , (c) i = r, 1, , 1, , 2, , A given ray of light suffers minimum deviation in an equilateral, prism P. Additional prisms Q and R of identical shape and material, are now added to P as shown in the figure. The ray will suffer, [IIT-JEE (Screening) 2001; KCET 2003], , (b) r = r, , (a) Greater deviation, , (d) All of these, , (b) Same deviation, , 1, , 1, , 3, , Which one of the following alternative is FALSE for a prism placed, in a position of minimum deviation, [MP PET 2001], (a) i = i, , 128., , n A B2 C4, , o, , 1, , 127., , (a), , 2, , In the visible region the dispersive powers and the mean angular, deviations for crown and flint glass prisms are , and d, d, respectively. The condition for getting deviation without dispersion, when the two prisms are combined is, , Q, P, , (c) No deviation, , R, , (d) Total internal reflection, 136., , In the given figure, what is the angle of prism, [Orissa JEE 2003], , [EAMCET 2001], , d d 0, , (a), , 129., , (b) B, , (d) (d ) ( d )2 0, , (c) d d 0, , 2, , A ray of light passes through the equilateral prism such that angle, of incidence is equal to the angle of emergence if the angle of, incidence is 45 . The angle of deviation will be, o, , (c) C, (d) D, , (a) 15, , (c) 60, 130., , o, , (b) 75, , o, , (d) 30, , o, , The solar spectrum during a complete solar eclipse is, , 138., , [Kerala PET 2002], , 131., , (a) Continuous, , (b) Emission line, , (c) Dark line, , (d) Dark band, , 132., , (d) Dispersion, , In the formation of a rainbow light from the sun on water droplets, undergoes, [CBSE PMT 2000;, Orissa JEE 2002; MP PET 2003; KCET 2004], , (a) Dispersion only, (b) Only total internal reflection, , o, , (a) 45, , o, , (b) 60, , (c) 90, , o, , (d) 180, , o, , o, , A convex lens, a glass slab, a glass prism and a solid sphere all are, made of the same glass, the dispersive power will be, (a) In the glass slab and prism, (b) In the lens and solid sphere, (c) Only in prism, (d) In all the four, , (b) Reflection, , (c) Scattering, , A prism of refractive index 2 has a refracting angle of 60 . At, what angle a ray must be incident on it so that it suffers a minimum, deviation, [BHU 2003; MP PMT 2005], , [CPMT 1986], , Why sun has elliptical shape on the time when rising and sun, setting ? It is due to, [AFMC 2002], (a) Refraction, , B, , A, , 137., , [Pb. PMT 2002], o, , C, , (a) A, , (b) d d 0, , 139., , A parallel beam of white light falls on a convex lens. Images of blue,, yellow and red light are formed on other side of the lens at a, distance of 0.20 m, 0.205 m and 0.214 m respectively. The dispersive, power of the material of the lens will be, (a) 619/1000, , (b) 9/200, , (c) 14/205, , (d) 5/214
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140., , The refractive index of the material of the prism for violet colour is, 1.69 and that for red is 1.65. If the refractive index for mean colour, is 1.66, the dispersive power of the material of the prism, (a) 0.66, , (b, , (c) 0.65, 141., , [JIPMER 1999], , 0.06, , (d) 0.69, , If the angle of prism is 60, , o, , and the angle of minimum deviation is, , o, , 40 , the angle of refraction will be, [MP PMT 2004], , 142., , 143., , (a), , 30 o, , (b) 60 o, , (c), , 100 o, , (d) 120 o, , The refractive index of a particular material is 1.67 for blue light,, 1.65 for yellow light and 1.63 for red light. The dispersive power of, the material is ........., [KCET 2004], (a) 0.0615, , (b) 0.024, , (c) 0.031, , (d) 1.60, , A ray of light is incident on an equilateral glass prism placed on a, horizontal table. For minimum deviation which of the following is, true, [IIT-JEE (Screening) 2004], (a) PQ is horizontal, , R, , (b) QR is horizontal, , Q, S, , (c) RS is horizontal, (d) Either PQ or RS is horizontal, 144., , P, , A beam of light composed of red and green ray is incident obliquely, at a point on the face of rectangular glass slab. When coming out on, the opposite parallel face, the red and green ray emerge from, , [CBSE PMT 2004], , (a) Two points propagating in two different directions, (b) Two points propagating in two parallel directions, (c) One point propagating in two different directions, (d) One point propagating in the same directions, 145., , 146., , White light is passed through a prism ........... colour shows minimum, deviation, [Orissa PMT 2004], (a) Red, , (b) Violet, , (c) Yellow, , (d) Green, , A ray of monochromatic light suffers minimum deviation of 38 o, while passing through a prism of refracting angle 60 o . Refractive, index of the prism material is, [Pb. PET 2001], (a) 1.5, , (b) 1.3, , (c) 0.8, 147., , (d) 2.4, , A ray incident a 15, , o, , on one refracting surface of a prism of angle, , o, , 60 , suffers a deviation of 55 o . What is the angle of emergence, o, , (a), , 95, , (c), , 30 o, , (b) 45, , o, , (d) None of these, , [DCE 2002]
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148., , The spectrum obtained from a sodium vapour lamp is an example of, [MH CET 2003], , 149., , 150., , 151., , (a) Absorption spectrum, (b) Emission spectrum, (c) Continuous spectrum, (d) Band spectrum, The sky would appear red instead of blue if, [DCE 2004], (a) Atmospheric particles scatter blue light more than red light, (b) Atmospheric particles scatter all colours equally, (c) Atmospheric particles scatter red light more than the blue light, (d) The sun was much hotter, Sir C.V. Raman was awarded Nobel Prize for his work connected, with which of the following phenomenon of radiation, (a) Scattering, (b) Diffraction, (c) Interference, (d) Polarisation, In absorption spectrum of Na the missing wavelength (s) are, , 9., , 10., , [CPMT 1983; AFMC 2005], , 11., , [BCECE 2005], , (a) 589 nm, (c) Both, , (b) 589.6 nm, (d) None of these, 12., , Human Eye and Lens Camera, 1., , 2., , A far sighted man who has lost his spectacles, reads a book by, looking through a small hole (3-4 mm) in a sheet of paper. The, reason will be, [CPMT 1977], (a) Because the hole produces an image of the letters at a longer, distance, (b) Because in doing so, the focal length of the eye lens is, effectively increased, (c) Because in doing so, the focal length of the eye lens is, effectively decreased, (d) None of these, For a normal eye, the least distance of distinct vision is, , 3., , (a) 0.25 m, (b) 0.50 m, (d) Infinite, (c) 25 m, For the myopic eye, the defect is cured by, , [CPMT 1984], , 4., , 5., , 6., , 13., , 14., , 7., , [MP PET/PMT 1988], , 8., , (a) Blind spot, (c) Red spot, Image formed on the retina is, , (b) Yellow spot, (d) None of the above, , (b) + 5 m, (a) – 100 m, (d) Very large, (c) – 5 m, A man can see only between 75 cm and 200 cm. The power of lens, to correct the near point will be, (a) + 8/3 D, (b) + 3 D, (d) – 8/3 D, (c) – 3 D, Image is formed for the short sighted person at, [AFMC 1988], , 15., , (a) Retina, (b) Before retina, (c) Behind the retina, (d) Image is not formed at all, A man can see the objects upto a distance of one metre from his, eyes. For correcting his eye sight so that he can see an object at, infinity, he requires a lens whose power is, or, A man can see upto 100 cm of the distant object. The power of the, lens required to see far objects will be, [MP PMT 1993, 2003], , 16., , (a) + 0.5 D, (b) + 1.0 D, (c) + 2.0 D, (d) – 1.0 D, A man can see the object between 15 cm and 30 cm. He uses the, lens to see the far objects. Then due to the lens used, the near point, will be at, (a), , 10, cm, 3, , (c) 15 cm, 17., , [CPMT 1972; MP PET/PMT 1988; CBSE PMT 1990], , (a) Concave lens, (b) Convex lens, (c) Cylindrical lens, (d) Prismatic lens, Circular part in the centre of retina is called, , [CPMT 1977; MP PET 1985, 88; MP PMT 1990], , (a) + 3.0 D, (b) + 0.125 D, (c) – 3.0 D, (d) + 4.0 D, How should people wearing spectacles work with a microscope, (a) They cannot use the microscope at all, (b) They should keep on wearing their spectacles, (c) They should take off spectacles, (d) (b) and (c) is both way, A man who cannot see clearly beyond 5 m wants to see stars clearly., He should use a lens of focal length, [MP PET/PMT 1988; Pb. PET 2003], , [CPMT 1990; KCET (Engg.) 2000], , (a) Convex lens, (b) Concave lens, (c) Cylindrical lens, (d) Toric lens, Lens used to remove long sightedness (hypermetropia) is, or, A person suffering from hypermetropia requires which type of, spectacle lenses, [MP PMT 1995], (a) Concave lens, (b) Plano-concave lens, (c) Convexo-concave lens, (d) Convex lens, Substance on the choroid is, (a) Japan black, (b) Nigrim pigment, (c) Carbon black, (d) Platinum black, Astigmatism (for a human eye) can be removed by using, , (a) Real and inverted, (b) Virtual and erect, (c) Real and erect, (d) Virtual and inverted, If there had been one eye of the man, then, (a) Image of the object would have been inverted, (b) Visible region would have decreased, (c) Image would have not been seen three dimensional, (d) (b) and (c) both, A person cannot see distinctly at the distance less than one metre., Calculate the power of the lens that he should use to read a book at, a distance of 25 cm, , 18., , (b) 30 cm, (d), , 100, cm, 3, , The far point of a myopia eye is at 40 cm. For removing this defect,, the power of lens required will be, [MP PMT 1987], (a) 40 D, (b) – 4 D, (c) – 2.5 D, (d) 0.25 D, A man suffering from myopia can read a book placed at 10 cm, distance. For reading the book at a distance of 60 cm with relaxed, vision, focal length of the lens required will be, [MP PMT 1989], , (a) 45 cm, , (b) – 20 cm
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19., , 20., , 21., , 22., , 23., , 24., , 25., , 26., , 27., , 28., , (c) – 12 cm, (d) 30 cm, If the distance of the far point for a myopia patient is doubled, the, focal length of the lens required to cure it will become, (a) Half, (b) Double, (c) The same but a convex lens, (d) The same but a concave lens, A presbyopic patient has near point as 30 cm and far point as 40, cm. The dioptric power for the corrective lens for seeing distant, objects is, (a) 40 D, (b) 4 D, (d) 0.25 D, (c) – 2.5 D, An imaginary line joining the optical centre of the eye lens and the, yellow point is called as, (a) Principal axis, (b) Vision axis, (c) Neutral axis, (d) Optical axis, The light when enters the human eye experiences most of the, refraction while passing through, (a) Cornea, (b) Aqueous humour, (c) Vitrous humour, (d) Crystalline lens, The impact of an image on the retina remains for, (a) 0.1 sec, (b) 0.5 sec, (c) 10 sec, (d) 15 sec, A person is suffering from myopic defect. He is able to see clear, objects placed at 15 cm. What type and of what focal length of lens, he should use to see clearly the object placed 60 cm away, (a) Concave lens of 20 cm focal length, (b) Convex lens of 20 cm focal length, (c) Concave lens of 12 cm focal length, (d) Convex lens of 12 cm focal length, , (c) – 10 D, 30., , 31., , 32., , 33., , 34., , (b) Blind spot, , (c) Cylindrical lens, , (d) Optic nerve, , When the power of eye lens increases, the defect of vision is, produced. The defect is known as, , A man with defective eyes cannot see distinctly object at the, distance more than 60 cm from his eyes. The power of the lens to, be used will be, [MP PMT 1994], (a) + 60 D, , (b) – 60 D, , (c) – 1.66 D, , (d), , 35., , 36., , A person's near point is 50 cm and his far point is 3 m. Power of, the lenses he requires for, (i) reading and, (ii) for seeing distant stars are, [MP PMT 1994], (b) 2 D and – 0.33 D, (a) – 2 D and 0.33 D, (c) – 2 D and 3 D, (d) 2 D and – 3 D, A person wears glasses of power – 2.5 D. The defect of the eye and, the far point of the person without the glasses are respectively, (a) Farsightedness, 40 cm, , (b) Nearsightedness, 40 cm, , (c) Astigmatism, 40 cm, , (d) Nearsightedness, 250 cm, , Myopia is due to, [AFMC 1996], (a) Elongation of eye ball, (b) Irregular change in focal length, (c) Shortening of eye ball, (d) Older age, A person is suffering from the defect astigmatism. Its main reason is, (a) Distance of the eye lens from retina is increased, , (b) Longsightedness, , (c) Colourblindness, , (d) None of the above, , A man is suffering from colour blindness for green colour. To, remove this defect, he should use goggles of, (a) Green colour glasses, , (b) Red colour glasses, , (c) Smoky colour glasses, , (d) None of the above, , (c) The cornea is not spherical, (d) Power of accommodation of the eye is decreased, 37., , KCET 2000; Pb. PET 2001], , [CPMT 1983], , (b) To and fro movement of the retina, , A person cannot see objects clearly beyond 2.0 m. The power of lens, required to correct his vision will be, [MP PMT/PET 1998; JIPMER 2000;, , (a) To and fro movement of eye lens, 38., , (a) + 2.0 D, , (b) – 1.0 D, , (c) + 1.0 D, , (d) – 0.5 D, , The resolving limit of healthy eye is about, [MP PET 1999; RPMT 1999; AIIMS 2001], , (c) Change in the convexity of the lens surface, (d) Change in the refractive index of the eye fluids, 29., , A short sighted person can see distinctly only those objects which lie, between 10 cm and 100 cm from him. The power of the spectacle, lens required to see a distant object is, [MP PET 1992], , (a) + 0.5 D, , (b) – 1.0 D, , 1, D, 1 . 66, , (b) Distance of the eye lens from retina is decreased, , (a) Shortsightedness, , In human eye the focussing is done by, , A person can see clearly only upto a distance of 25 cm. He wants to, 1989]at a distance of 50 cm. What kind of lens does, read a [MP, bookPET, placed, he require for his spectacles and what must be its power, (a) Concave, – 1.0 D, (b) Convex, + 1.5 D, (d) Convex, + 2.0 D, (c) Concave, – 2.0 D, The human eye has a lens which has a, [MP PET 1994], (a) Soft portion at its centre, (b) Hard surface, (c) Varying refractive index, (d) Constant refractive index, , [MP PMT 1991], , The sensation of vision in the retina is carried to the brain by, (a) Ciliary muscles, , (d) + 4.0 D, , 1 , (a) 1 or , , 60 , , (c) 1 o, , , , (b) 1 , , (d), , 1, ", 60
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39., , When objects at different distances are seen by the eye, which of the, following remains constant, [MP PMT 1999], , 48., , (a) The focal length of the eye lens, , A man cannot see clearly the objects beyond a distance of 20 cm, from his eyes. To see distant objects clearly he must use which kind, of lenses and of what focal length, [MP PMT 2000], , (b) The object distance from the eye lens, (c) The radii of curvature of the eye lens, (d) The image distance from the eye lens, 40., , 41., , A person wears glasses of power – 2.0 D. The defect of the eye and, the far point of the person without the glasses will be, (a) Nearsighted, 50 cm, , (b) Farsighted, 50 cm, , (c) Nearsighted, 250 cm, , (d) Astigmatism, 50 cm, , An eye specialist prescribes spectacles having a combination of, convex lens of focal length 40 cm in contact with a concave lens of, focal length 25 cm. The power of this lens combination in diopters, is, , 49., , 42., , 50., , 43., , (I), (II), , Presbiopia, Hypermetropia, , (A), (B), , (III), , Astigmatism, , (C), , (IV), , Myopia, , (D), , Sphero-cylindrical lens, Convex lens of proper, power may be used close, to the eye, Concave lens of suitable, focal length, Bifocal lens of suitable focal, length, , (a) I-A; II-C; III-B; IV-D, , (b) I-B; II-D; III-C; IV-A, , (c) I-D; II-B; III-A; IV-C, , (d) I-D; II-A; III-C; IV-B, , 51., , 52., , [EAMCET (Med.) 1995; MP PET 2001; BCECE 2004], , 44., , 45., , 46., , 47., , (a) 0 and 25 cm, , (b) 0 and , , (c) 25 cm and 100 cm, , (d) 25 cm and , , 54., , Two parallel pillars are 11 km away from an observer. The minimum, distance between the pillars so that they can be seen separately will, be, [RPET 1997; RPMT 2000], (a) 3.2 m, , (b) 20.8 m, , (c) 91.5 m, , (d) 183 m, , (b) Long- side defect, , (c) Bad vision due to old age, , (d) None of these, , 55., , (a) 100 cm, (b) 150 cm, (c) 50 cm, (d) 25 cm, A person, [ISMsuffering, Dhanbad from, 1994] 'presbyopia' (myopia and hyper metropia, both defects) should use, [MP PET 2001], (a) A concave lens, (b) A convex lens, (c) A bifocal lens whose lower portion is convex, (d) A bifocal lens whose upper portion is convex, A person who can see things most clearly at a distance of 10 cm., Requires spectacles to enable to him to see clearly things at a, distance of 30 cm. What should be the focal length of the spectacles, (a) 15 cm (Concave), (b) 15 cm (Convex), (c) 10 cm, (d) 0, Far points of myopic eye is 250 cm, then the focal length of the lens, to be used will be, [DPMT 2002], (b) – 250/9 cm, (a) – 250 cm, (c) + 250 cm, (d) + 250/9 cm, A man can see clearly up to 3 metres. Prescribe a lens for his, spectacles so that he can see clearly up to 12 metres, (b) 3 D, (a) – 3/4 D, (c) – 1/4 D, (d) – 4 D, A satisfactory photographic print is obtained when the exposure, time is 10 sec at a distance of 2 m from a 60 cd lamp. The time of, exposure required for the same quality print at a distance of 4 m, from a 120 cd lamp is, [Kerala PMT 2002], , 56., , (b) 10 sec, (a) 5 sec, (c) 15 sec, (d) 20 sec, A person can not see the objects clearly placed at a distance more, than 40 cm. He is advised to use a lens of power, [DCE 2002; MP PMT 2002, 03], , Amount of light entering into the camera depends upon, [DCE 2000], , (a), (b), (c), (d), , [MP PET 2000], , (a) Short sightedness or myopia, (b) Long sightedness or hypermetropia, (c) Presbyopia, (d) Astigmatism, To remove myopia (short sightedness) a lens of power 0.66 D is, required. The distant point of the eye is approximately, , [DPMT 2002], , Retina of eye acts like ........ of camera [AFMC 2003], (a) Shutter, (b) Film, (c) Lens, (d) None of these, The hyper-metropia is a, [CBSE PMT 2000], (a) Short-side defect, , (d) 20 cm concave, , [BHU 2003; CPMT 2004; PM PMT 2005], , 53., , Near and far points of a human eye are, , (c) 20 cm convex, , A person uses spectacles of power +2D. He is suffering from, , [MP PMT 2001], , (b) – 1.5, (d) – 6.67, , Match the List I with the List II from the combinations shown, , (b) 100 cm concave, , [MP PMT 1999], , [IIT 1997 Cancelled; DPMT 2000], , (a) + 1.5, (c) + 6.67, , (a) 100 cm convex, , Focal length of the objective lens, Product of focal length and diameter of the objective lens, Distance of the object from camera, Aperture setting of the camera, , 57., , (a) – 2.5 D, (b) + 2.5 D, (c) – 6.25 D, (d) + 1.5 D, A person uses a lens of power + 3D to normalise vision. Near point, of hypermetropic eye is, [CPMT 2002], (a) 1 m, (b) 1.66 m, (c) 2 m, (d) 0.66 m
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58., , 59., , A defective eye cannot see close objects clearly because their image, is formed, [MP PET 2003], (a) On the eye lens, (b) Between eye lens and retina, (c) On the retina, (d) Beyond retina, Image formed on retina of eye is proportional to, , (d) 4 correction for far-sightedness, , Microscope and Telescope, 1., , [RPMT 2001], , (a) Size of object, Size of object, (c), Size of image, 60., , (b) Area of object, size of image, (d), size of object, , 2., , A student can distinctly see the object upto a distance 15 cm. He, wants to see the black board at a distance of 3 m. Focal length and, power of lens used respectively will be, , 3., , [Pb. PMT 2003], , 61., , (a), , 4.8 cm, 3.3 D, , (b) 5.8 cm, 4.3 D, , (c), , 7.5 cm, 6.3 D, , (d) 15.8 cm, 6.3 D, , A camera objective has an aperture diameter d. If the aperture is, reduced to diameter d / 2, the exposure time under identical, conditions of light should be made, , 4., , [Kerala PMT 2004], , (a), 62., , 2 fold, , (b) 2 fold, , (c) 2 2 fold, (d) 4 fold, The light gathering power of a camera lens depends on, , The focal lengths of the objective and eye-lens of a microscope are 1, , cm and 5 cm respectively. If the magnifying power for the relaxed, , 5., , eye is 45, then the length of the tube is, (a) 30 cm, (b) 25 cm, (d) 12 cm, (c) 15 cm, In a compound microscope magnification will be large, if the focal, length of the eye piece is, [CPMT 1984], (a) Large, (b) Smaller, (c) Equal to that of objective, (d) Less than that of objective, The focal length of the objective lens of a compound microscope is [CPMT 1985, (a) Equal to the focal length of its eye piece, (b) Less than the focal length of eye piece, (c) Greater than the focal length of eye piece, (d) Any of the above three, Microscope is an optical instrument which, (a) Enlarges the object, (b) Increases the visual angle formed by the object at the eye, (c) Decreases the visual angle formed by the object at the eye, (d) Brings the object nearer, Magnifying power of a simple microscope is (when final image is, formed at D = 25 cm from eye), , [DCE 2003], , (a), (b), (c), (d), 63., , [MP PET 1996; BVP 2003], , Its diameter only, Ratio of focal length and diameter, Product of focal length and diameter, Wavelength of light used, , (a), , f, 1, The exposure time of a camera lens at the, setting is, 2 .8, 200, f, second. The correct time of exposure at, is, 5 .6, , D, f, , (c) 1 , 6., , f, D, , (b) 1 , , D, f, , (d) 1 , , D, f, , If in compound microscope m and m be the linear magnification of, the objective lens and eye lens respectively, then magnifying power, of the compound microscope will be, 1, , 2, , [DCE 2003], , 64., , [CPMT 1985; KCET 1994], , (b) 0.02 sec, (a) 0.4 sec, (c) 0.002 sec, (d) 0.04 sec, Ability of the eye to see objects at all distances is called, , (a) m 1 m 2, (c), , [AFMC 2005], , (a) Binocular vision, (c) Hypermetropia, , (b) Myopia, (d) Accommodation, , 65., , 7., [KCET 2005], , 1., F, , 8., 2., , 3., , 9., , 4., Identify the wrong description of the above figures, (a) 1 represents far-sightedness, (b) 2 correction for short sightedness, (c) 3 represents far sightedness, , 10., , (m 1 m 2 ) / 2, , (b), , m1 m 2, , (d) m 1 m 2, , For which of the following colour, the magnifying power of a, microscope will be maximum, (a) White colour, (b) Red colour, (c) Violet colour, (d) Yellow colour, The length of the compound microscope is 14 cm. The magnifying, power for relaxed eye is 25. If the focal length of eye lens is 5 cm,, then the object distance for objective lens will be, (a) 1.8 cm, (b) 1.5 cm, (c) 2.1 cm, (d) 2.4 cm, If the focal length of objective and eye lens are 1.2 cm and 3 cm, respectively and the object is put 1.25 cm away from the objective, lens and the final image is formed at infinity. The magnifying power, of the microscope is, (a) 150, (b) 200, (c) 250, (d) 400, The focal length of objective and eye lens of a microscope are 4 cm, and 8 cm respectively. If the least distance of distinct vision is 24 cm, and object distance is 4.5 cm from the objective lens, then the, magnifying power of the microscope will be
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11., , 12., , (a) 18, (b) 32, (c) 64, (d) 20, When the length of a microscope tube increases, its magnifying, power, [MNR 1986], (a) Decreases, (b) Increases, (c) Does not change, (d) May decrease or increase, In a compound microscope, if the objective produces an image I and, the eye piece produces an image I , then, o, , (a) The focal lengths of the objective and the eye piece should be, small, (b) Objective should have small focal length and the eye piece large, (c) Both should have large focal lengths, (d) The objective should have large focal length and eye piece, should have small, 22., , If the focal length of the objective lens is increased then, [MP PMT 1994], , e, , [MP PET 1990], , (a) I is virtual but I is real, (b) I is real but I is virtual, (c) I and I are both real, (d) I and I are both virtual, The magnifying power of a simple microscope can be increased, if, we use eye-piece of, [MP PMT 1986], (a) Higher focal length, (b) Smaller focal length, (c) Higher diameter, (d) Smaller diameter, An electron microscope is superior to an optical microscope in, (a) Having better resolving power, (b) Being easy to handle, (c) Low cost, (d) Quickness of observation, The magnifying power of a microscope with an objective of 5 mm, focal length is 400. The length of its tube is 20 cm. Then the focal, length of the eye-piece is, [MP PMT 1991], (a) 200 cm, (b) 160 cm, (d) 0.1 cm, (c) 2.5 cm, The maximum magnification that can be obtained with a convex lens, of focal length 2.5 cm is (the least distance of distinct vision is 25, cm), [MP PET 2003], (a) 10, (b) 0.1, (c) 62.5, (d) 11, When the object is self-luminous, the resolving power of a, microscope is given by the expression, o, , o, , 13., , 14., , 15., , 16., , 17., , 18., , (a) Magnifying power of microscope will increase but that of, telescope will decrease, , e, , (b) Magnifying power of microscope and telescope both will, increase, , e, , o, , e, , o, , e, , (a), , 2 sin, 1 .22 , , (b), , (c), , 2 cos , 1 .22 , , (d), , (c) Magnifying power of microscope and telescope both will, decrease, (d) Magnifying power of microscope will decrease but that of, telescope will increase, 23., , [Manipal MEE 1995; DPMT 2002], , 24., , , , (a) 19, , (b) 31, , (c) 150, , (d), , The focal lengths of the objective and the eye-piece of a compound, microscope are 2.0 cm and 3.0 cm respectively. The distance, between the objective and the eye-piece is 15.0 cm. The final image, formed by the eye-piece is at infinity. The two lenses are thin. The, distances in cm of the object and the image produced by the, objective measured from the objective lens are respectively [IIT 1995], (a) 2.4 and 12.0, , (b) 2.4 and 15.0, , (c) 2.3 and 12.0, , (d) 2.3 and 3.0, , Resolving power of a microscope depends upon, , 26., , (a) The focal length and aperture of the eye lens, (b) The focal lengths of the objective and the eye lens, (c) The apertures of the objective and the eye lens, (d) The wavelength of light illuminating the object, The objective lens of a compound microscope produces, magnification of 10. In order to get an overall magnification of 100, when image is formed at 25 cm from the eye, the focal length of the, eye lens should be, (a) 4 cm, (b) 10 cm, , [MP PET 1995], , The power of two convex lenses A and B are 8 diopters and 4, diopters respectively. If they are to be used as a simple microscope,, the magnification of, (a) B will be greater than A, , (c), , (b) A will be greater than B, (c) The information is incomplete, , 27., , (d) None of the above, 19., , 20., , Finger prints are observed by the use of, (a) Telescope, , (b) Microscope, , (c) Gallilean telescope, , (d) Concave lens, , To produce magnified erect image of a far object, we will be, required along with a convex lens, is [MNR 1983], (a) Another convex lens, , 21., , 28., , 25, cm, 9, , (d) 9 cm, , A person using a lens as a simple microscope sees an, (a) Inverted virtual image, (b) Inverted real magnified image, (c) Upright virtual image, (d) Upright real magnified image, Least distance of distinct vision is 25 cm. Magnifying power of, simple microscope of focal length 5 cm is, [EAMCET (Engg.) 1995; Pb. PMT 1999], , (b) Concave lens, , (c) A plane mirror, (d) A concave mirror, In order to increase the magnifying power of a compound, microscope, [JIPMER 1986; MP PMT 1997], , 150, , 25., , sin, , 2, , The magnification produced by the objective lens and the eye lens of, [CPMT 1984], a compound microscope, are 25 and 6 respectively. The magnifying, power of this microscope is, , 29., , (a) 1 / 5, (b) 5, (c) 1 / 6, (d) 6, The objective of a compound microscope is essentially
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[SCRA 1998], , 30., , (a) A concave lens of small focal length and small aperture, (b) Convex lens of small focal length and large aperture, (c) Convex lens of large focal length and large aperture, (d) Convex lens of small focal length and small aperture, Resolving power of a microscope depends upon, , 38., , 39., , [DCE 1999], , 31., , (a) Wavelength of light used, directly, (b) Wavelength of light used, inversely, (c) Frequency of light used, (d) Focal length of objective, In a compound microscope cross-wires are fixed at the point, , 32., , 40., , 33., , 41., , 34., , (b) 23, , (c) 166, , (d) 500, , 35., , (a) 10, , (b) 20, , (c) 50, , (d) 25, , The angular magnification of a simple microscope can be increased, by increasing, [Orissa JEE 2002], (a) Focal length of lens, (b) Size of object, , 42., , Wavelength of light used in an optical instrument are 1 4000 Å, , (a) 16 : 25, , (b) 9 : 1, , (c) 4 : 5, , (d) 5 : 4, , The separation between two microscopic particles is measured P A, and PB by two different lights of wavelength 2000 Å and 3000 Å, respectively, then, [AIEEE 2002], , 43., , 44., , (a), , PA PB, , (b), , PA PB, , (c), , PA 3 / 2 PB, , (d), , PA PB, , The image formed by an objective of a compound microscope is, (a) Virtual and enlarged, , (b) Virtual and diminished, , (c) Real and diminished, , (d) Real and enlarged, , An achromatic telescope objective is to be made by combining the, lenses of flint and crown glasses. This proper choice is, , (c) Real, inverted and magnified, (d) Virtual, erect and reduced, , (a) Convergent of crown and divergent of flint, , The magnifying power of a compound microscope increases when, , [MP PET 2000], (c) Both, divergent, , (a) The focal length of objective lens is increased and that of eye, lens is decreased, , (d) Both convergent, , (b) Divergent of crown and convergent of flint, , (b) The focal length of eye lens is increased and that of objective, lens is decreased, , 45., , If F and F are the focal length of the objective and eye-piece, respectively of a telescope, then its magnifying power will be [CPMT 1977, 82, 97, o, , e, , SCRA 1994; KCET 1999; Pb. PMT 2000; BHU 2001;, , (c) Focal lengths of both objective and eye-piece are increased, , DCE 2002; RPMT 2003; BCECE 2003, 04], , (d) Focal lengths of both objective and eye-piece are decreased, 36., , If the red light is replaced by blue light illuminating the object in a, microscope the resolving power of the microscope, (a) Decreases, (b) Increases, (c) Gets halved, , 37., , (d) Power of lens, , [AIEEE 2002], , [IIT-JEE (Screening) 2000; MP PET 2005], , (b) Real, erect and magnified, , A compound microscope has two lenses. The magnifying power of, one is 5 and the combined magnifying power is 100. The magnifying, power of the other lens is, , (corresponding to 1 and 2 ) is, , In a compound microscope, the intermediate image is, (a) Virtual, erect and magnified, , (d) 0.06 mm, , and 2 5000 Å, then ratio of their respective resolving power, , [MP PMT 2000], , (a) 5, , (b) 0.10 mm, , (c) 0.12 mm, , (c) Aperture of lens, , [EAMCET (Med.) 2000], , (a) 6.00 cm, (b) 7.75 cm, (c) 9.25 cm, (d) 11.00 cm, The length of the tube of a microscope is 10 cm. The focal lengths of, the objective and eye lenses are 0.5 cm and 1.0 cm. The magnifying, power of the microscope is about, , (a) 0.08 mm, , [Kerala PMT 2002], , [EAMCET (Engg.) 2000], , (a) Where the image is formed by the objective, (b) Where the image is formed by the eye-piece, (c) Where the focal point of the objective lies, (d) Where the focal point of the eye-piece lies, In a compound microscope, the focal lengths of two lenses are 1.5, cm and 6.25 cm an object is placed at 2 cm form objective and the, final image is formed at 25 cm from eye lens. The distance between, the two lenses is, , Two points separated by a distance of 0.1 mm can just be resolved, in a microscope when a light of wavelength 6000 Å is used. If the, light of wavelength 4800Å is used this limit of resolution becomes, , (d) Remains unchanged, , (a), , Fo Fe, , (c), , Fo / Fe, , (b), , Fo Fe, , (d), , 1, (Fo Fe ), 2, , [DCE 2001], , 46., , The magnifying power of a telescope can be increased by, , The magnifying power of a simple microscope is 6. The focal length, of its lens in metres will be, if least distance of distinct vision is, 25 cm, [MP PMT 2001], , (a) Increasing focal length of the system, , (a) 0.05, , (b) 0.06, , (b) Fitting eye piece of high power, , (c) 0.25, , (d) 0.12, , (c) Fitting eye piece of low power, , [CPMT 1979], , (d) Increasing the distance of objects
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47., , A simple telescope, consisting of an objective of focal length 60 cm, and a single eye lens of focal length 5 cm is focussed on a distant, object is such a way that parallel rays comes out from the eye lens., If the object subtends an angle 2 at the objective, the angular width, of the image, , [MH CET 2001], , o, , 56., , [CPMT 1979; NCERT 1980;, MP PET 1992; JIPMER 1997; UPSEAT 2001], , (a) 10, , (b) 24, , o, , (c) 50, (d) 1/6, The diameter of the objective of the telescope is 0.1 metre and, wavelength of light is 6000 Å. Its resolving power would be, approximately, [MP PET 1997], o, , 48., , (a), 49., , o, , o, , 7.32 10 6 rad, , 57., , (b) 1.36 10 6 rad, , (c) 7.32 10 5 rad, (d) 1.36 10 5 rad, A photograph of the moon was taken with telescope. Later on, it, was found that a housefly was sitting on the objective lens of the, telescope. In photograph, , 58., , [NCERT 1970; MP PET 1999], , 50., , o, , (a) The image of housefly will be reduced, (b) There is a reduction in the intensity of the image, (c) There is an increase in the intensity of the image, (d) The image of the housefly will be enlarged, For a telescope to have large resolving power the, , 53., , 54., , (a) 10 times taller, (b) 15 times taller, (c) 10 times nearer, (d) 15 times nearer, The focal length of objective and eye lens of a astronomical telescope, are respectively 2 m and 5 cm. Final image is formed at (i) least, distance of distinct vision (ii) infinity. The magnifying power in both, cases will be, [MP PMT/PET 1988], (a) – 48, – 40, (b) – 40, – 48, (c) – 40, 48, (d) – 48, 40, For observing a cricket match, a binocular is preferred to a, terrestrial telescope because, (a) The binocular gives the proper three dimensional view, (b) The binocular has shorter length, (c) The telescope does not give erect image, (d) Telescope have chromatic aberrations, To increase the magnifying power of telescope (f = focal length of, the objective and f = focal length of the eye lens), , 59., , 60., , o, , 61., , 62., , 63., , [MP PET/PMT 1988; MP PMT 1992, 94], , (a) f should be large and f should be small, (b) f should be small and f should be large, (c) f and f both should be large, (d) f and f both should be small, Relative difference of focal lengths of objective and eye lens in the, microscope and telescope is given as, e, , 55., , e, , o, , e, , o, , e, , e, , o, , e, , o, , e, , [DPMT 1999], , e, , o, , e, , o, , (a) Focal length of its objective should be large, (b) Focal length of its eye piece should be large, (c) Focal length of its eye piece should be small, (d) Aperture of its objective should be large, An observer looks at a tree of height 15 m with a telescope of, magnifying power 10. To him, the tree appears, , o, , (a) f = 45 cm and f = – 9 cm, (b) f = 7.2 cm and f = 5 cm, (c) f = 50 cm and f = 10 cm, (d) f = 30 cm and f = 6 cm, In an astronomical telescope, the focal lengths of two lenses are 180, cm and 6 cm respectively. In normal adjustment, the magnifying, power will be, [MP PET 1990], (a) 1080, (b) 200, (c) 30, (d) 186, The magnifying power of an astronomical telescope for relaxed, vision is 16. On adjusting, the distance between the objective and eye, lens is 34 cm. Then the focal length of objective and eye lens will be, respectively, [MP PMT 1989], (a) 17 cm, 17 cm, (b) 20 cm, 14 cm, (c) 32 cm, 2 cm, (d) 30 cm, 4 cm, In Gallilean telescope, if the powers of an objective and eye lens are, respectively +1.25 D and – 20 D, then for relaxed vision, the length, and magnification will be, (a) 21.25 cm and 16, (b) 75 cm and 20, (d) 8.5 cm and 21.25, (c) 75 cm and 16, The aperture of a telescope is made large, because, o, , [CPMT 1975], , 52., , e, , [IIT 1989; MP PET 1995; JIPMER 2000], , [CPMT 1980, 81, 85; MP PET 1994;, DCE 2001; AFMC 2005], , 51., , (a) It is equal in both, (b) It is more in telescope, (c) It is more in microscope (d), It may be more in any one, If the telescope is reversed i.e. seen from the objective side, (a) Object will appear very small, (b) Object will appear very large, (c) There will be no effect on the image formed by the telescope, (d) Image will be slightly greater than the earlier one, The focal length of the objective of a terrestrial telescope is 80 cm, and it is adjusted for parallel rays, then its magnifying power is 20., If the focal length of erecting lens is 20 cm, then full length of, telescope will be, (a) 84 cm, (b) 100 cm, (d) 164 cm, (c) 124 cm, An astronomical telescope has an angular magnification of, magnitude 5 for distant objects. The separation between the, objective and the eye piece is 36 cm and the final image is formed, at infinity. The focal length f of the objective and the focal length f, of the eye piece are, , 64., , (a) To increase the intensity of image, (b) To decrease the intensity of image, (c) To have greater magnification, (d) To have lesser resolution, In Gallilean telescope, the final image formed is, (a) Real, erect and enlarged, (b) Virtual, erect and enlarged, (c) Real, inverted and enlarged, (d) Virtual, inverted and enlarged, The magnifying power of a telescope is 9. When it is adjusted for, parallel rays, the distance between the objective and the eye-piece is, found to be 20 cm. The focal length of the two lenses are, (a) 18 cm, 2 cm, (b) 11 cm, 9 cm
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65., , 66., , (c) 10 cm, 10 cm, (d) 15 cm, 5 cm, The focal length of the objective and eye piece of a telescope are, respectively 60 cm and 10 cm. The magnitude of the magnifying, power when the image is formed at infinity is, (a) 50, (b) 6, (c) 70, (d) 5, The magnifying power of an astronomical telescope is 8 and the, distance between the two lenses is 54 cm. The focal length of eye, lens and objective lens will be respectively, , (a) The total length of an astronomical telescope is the sum of the, focal lengths of its two lenses, (b) The image formed by the astronomical telescope is always erect, [MP PETthe, 1991], because, effect of the combination of the two lenses is, divergent, (c) The magnification of an astronomical telescope can be increased, by decreasing the focal length of the eye-piece, (d) The magnifying power of the refracting type of astronomical, telescope is the ratio of the focal length of the objective to that, of the eye-piece, , [MP PMT 1991; CPMT 1991; Pb. PMT 2001], , 67., , 68., , (a) 6 cm and 48 cm, (b) 48 cm and 6 cm, (c) 8 cm and 64 cm, (d) 64 cm and 8 cm, An opera glass (Gallilean telescope) measures 9 cm from the, objective to the eyepiece. The focal length of the objective is 15 cm., Its magnifying power is, [DPMT 1988], (a) 2.5, (b) 2/5, (c) 5/3, (d) 0.4, When a telescope is adjusted for parallel light, the distance of the, objective from the eye piece is found to be 80 cm. The magnifying, power of the telescope is 19. The focal lengths of the lenses are, , 76., , A terrestrial telescope is made by introducing an erecting lens of, focal length f between the objective and eye piece lenses of an, astronomical telescope. This causes the length of the telescope tube, to increase by an amount equal to, [KCEE 1996], , 77., , (a) f, (b) 2f, (c) 3f, (d) 4f, The length of an astronomical telescope for normal vision (relaxed, eye) (f = focal length of objective lens and f = focal length of eye, lens) is, , [MP PMT 1992; Very similar to DPMT 2004], , 69., , 70., , 71., , 72., , (a) 61 cm, 19 cm, (b) 40 cm, 40 cm, (c) 76 cm, 4 cm, (d) 50 cm, 30 cm, A reflecting telescope utilizes, [CPMT 1983], (a) A concave mirror, (b) A convex mirror, (c) A prism, (d) A plano-convex lens, The aperture of the objective lens of a telescope is made large so as, to, [AIEEE 2003; KCET 2003], (a) Increase the magnifying power of the telescope, (b) Increase the resolving power of the telescope, (c) Make image aberration less, (d) Focus on distant objects, On which of the following does the magnifying power of a telescope, depends, [MP PET 1992], (a) The focal length of the objective only, (b) The diameter of aperture of the objective only, (c) The focal length of the objective and that of the eye piece, (d) The diameter of aperture of the objective and that of the eye, piece, Large aperture of telescope are used for, , [EAMCET (Med.) 1995; CPMT 1999; BVP 2003], , 78., , 79., , 74., , 75., , (b) 0.25 m, , (c) 0.175 m, , (d) 0.15 m, , 80., , 81., , The diameter of the objective lens of a telescope is 5.0 m and, wavelength of light is 6000 Å. The limit of resolution of this, telescope will be, [MP PMT 1994], (a) 0.03 sec, , (b) 3.03 sec, , (c) 0.06 sec, , (d) 0.15 sec, [Manipal MEE 1995], , (b), , fo, fe, , (c), , fo fe, , (d), , fo fe, , A Gallilean telescope has objective and eye-piece of focal lengths 200, cm and 2 cm respectively. The magnifying power of the telescope, for normal vision is, (a) 90, (b) 100, (c) 108, (d) 198, In an astronomical telescope, the focal length of the objective lens is, 100 cm and of eye-piece is 2 cm. The magnifying power of the, telescope for the normal eye is, (a) 50, , (b) 10, , (c) 100, , (d), , 1, 50, , When diameter of the aperture of the objective of an astronomical, telescope is increased, its, [MP PMT 1997], (a) Magnifying power is increased and resolving power is, decreased, (b) Magnifying power and resolving power both are increased, (c) Magnifying power remains the same but resolving power is, increased, [MNR 1994], (d) Magnifying power and resolving power both are decreased, The focal lengths of the objective and eye lenses of a telescope are, respectively 200 cm and 5 cm. The maximum magnifying power of, the telescope will be, [MP PMT/PET 1998; JIPMER 2001, 02], , 82., , All of the following statements are correct except, , fo fe, , [MP PET 1997], , (a) Large image, (b) Greater resolution, (c) Reducing lens aberration (d) Ease of manufacture, Two convex lenses of focal lengths 0.3 m and 0.05 m are used to, make a telescope. The distance kept between the two is, (a) 0.35 m, , (a), , [MP PMT 1996], , [CPMT 1981; MP PMT 1995; AFMC 2000], , 73., , e, , o, , (a) – 40, , (b) – 48, , (c) – 60, , (d) – 100, , The minimum magnifying power of a telescope is M, If the focal, length of its eye lens is halved, the magnifying power will become, (a) M / 2, , (b) 2 M, , (c) 3 M, , (d) 4 M
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83., , The astronomical telescope consists of objective and eye-piece. The, focal length of the objective is, , (a), , 45 cm, , (b) 55 cm, , [AIIMS 1998; BHU 2000], , (c), , 275, cm, 6, , (d), , (a) Equal to that of the eye-piece, 93., , (b) Greater than that of the eye-piece, (c) Shorter than that of the eye-piece, 84., , 86., , 0 .5 o at the eye. If it is looked through the telescope, the angle, subtended by the moon's image will be, , Four convergent lenses have focal lengths 100 cm, 10 cm, 4 cm and, 0.3 cm. For a telescope with maximum possible magnification, we, choose the lenses of focal length, , (a) 100 o, , (a) 100 cm, 0.3 cm, (b) 10 cm, 0.3 cm, (c) 10 cm, 4 cm, (d) 100 cm, 4 cm, The focal length of objective and eye-piece of a telescope are 100 cm, and 5 cm respectively. Final image is formed at least distance of, distinct vision. The magnification of telescope is, (a) 20, (b) 24, (c) 30, (d) 36, A planet is observed by an astronomical refracting telescope having, an objective of focal length 16 m and an eye-piece of focal length 2, , 94., , 95., , 96., , (d) The objective is larger than the eye-piece, , 89., , 97., , (b) 40 cm, , (c) 44 cm, , (d) 440 cm, , If both the object and image are at infinite distances form a, refracting telescope its magnifying power will be equal to, , 98., , 99., , [AMU (Engg.) 1999], , (b) The difference of the focal lengths of the two lenses, (c) The ratio of the focal length of the objective and eyepiece, (d) The ratio of the focal length of the eyepiece and objective, The number of lenses in a terrestrial telescope is, , 92., , (c) Four, , (d) Six, , (b) 1.4 cm, (a) 0.7 cm, (c) 2.8 cm, (d) Zero (i.e. point image), In a terrestrial telescope, the focal length of objective is 90 cm, of, inverting lens is 5 cm and of eye lens is 6 cm. If the final image is at, 30 cm, then the magnification will be, (a) 21, (b) 12, (c) 18 [AFMC 1994], (d) 15, The resolving power of a telescope depends on, (a) Focal length of eye lens, (b) Focal length of objective lens, (c) Length of the telescope, (d) Diameter of the objective lens, Four lenses of focal length + 15 cm, + 20cm, + 150cm and + 250, cm are available for making an astronomical telescope. To produce, the largest magnification, the focal length of the eye-piece should be, (a) + 15 cm, (b) + 20 cm, (c) +150 cm, (d) + 250 cm, In an astronomical telescope, the focal length of objective lens and, eye-piece are 150 cm and 6 cm respectively. In case when final image, is formed at least distance of distinct vision. the magnifying power is, [KCET 2001], , (a) 20, (c) 60, 100., , [KCET 1999; MH CET 2003], , (b) Three, , The sun's diameter is 1.4 10 m and its distance from the earth, , [CPMT 2001; AIIMS 2001], , (a) 4 cm, , (a) Two, , (d) a /(1.22 ), 9, , [MP PET 2000, 01; DCE 2003], , (a) The sum of the focal lengths of the objective and the eyepiece, , 91., , [RPET 1997], /(1.22a), m, , [DPMT 2001], , If tube length of astronomical telescope is 105 cm and magnifying, power is 20 for normal setting, calculate the focal length of objective, (a) 100 cm, (b) 10 cm, (c) 20 cm, (d) 25 cm, The length of a telescope is 36 cm. The focal lengths of its lenses, can be, [Bihar MEE 1995], (a) 30 cm, 6 cm, (b) – 30 cm, – 6 cm, (d) – 30 cm, 6 cm, (c) 30 cm, – 6 cm, An astronomical telescope of ten-fold angular magnification has a, length of 44 cm. The focal length of the objective is, [CBSE PMT 1997], , 90., , (b) (1.22 a) / , , is 10 11 m. The diameter of its image, formed by a convex lens of, focal length 2 m will be, [MP PET 2000], , (c) The image of the planet is inverted, , 88., , (c) 25 o, (d) 10 o, The diameter of the objective of a telescope is a, its magnifying, power is m and wavelength of light is . The resolving power of the, telescope is, [MP PMT 2000], , (c), , (a) The distance between the objective and the eye-piece is 16.02 m, (b) The angular magnification of the planet is 800, , (b) 50 o, , (a) (1.22 ) / a, , cm [IIT-JEE 1992; Roorkee 2000], , 87., , The focal lengths of the objective and eye-piece of a telescope are, respectively 100 cm and 2 cm. The moon subtends an angle of, , (d) Five times shorter than that of the eye-piece, , [KCET 1994], , 85., , 325, cm, 6, , (b) 30, (d) 15, , In a laboratory four convex lenses L1 , L 2 , L3 and L 4 of focal, lengths 2, 4, 6 and 8 cm respectively are available. Two of these, lenses form a telescope of length 10 cm and magnifying power 4., The objective and eye lenses are, [MP PMT 2001], , The focal lengths of the lenses of an astronomical telescope are 50, cm and 5 cm. The length of the telescope when the image is formed, at the least distance of distinct vision is, [EAMCET (Engg.) 2000], , 101., , (a), , L 2 , L3, , (b), , L1 , L 4, , (c), , L3 , L 2, , (d), , L 4 , L1, , A telescope has an objective of focal length 50 cm and an eye piece, of focal length 5 cm. The least distance of distinct vision is 25 cm.
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The telescope is focussed for distinct vision on a scale 200 cm away., The separation between the objective and the eye-piece is, (a) 75 cm, (b) 60 cm, 102., , (c) 71 cm, (d) 74 cm, The resolving power of a telescope whose lens has a diameter of 1.22, m for a wavelength of 5000 Å is, , (c) Much greater than fo or fe, , [Kerala PET 2002], , (d) Much less than fo or fe, (e) Need not depend either value of focal lengths, 110., , [Kerala PMT 2002], , 103., , (a), , 2 10, , 5, , (c), , 2 10, , 2, , (b), , 2 10, , (d), , 2 10 4, , 6, , To increase both the resolving power and magnifying power of a, telescope, [Kerala PET 2002; KCET 2002], (a) Both the focal length and aperture of the objective has to be, increased, , 111., , (a), , fo fe, , (b), , fo fe, , (c), , fo fe, , (d) None of these, , The angular resolution of a 10 cm diameter telescope at a, wavelength of 5000 Å is of the order [CBSE PMT 2005], , (b) The focal length of the objective has to be increased, , (a) 10 6 rad, , (b) 10 2 rad, , (c) The aperture of the objective has to be increased, , (c) 10 4 rad, , (d) 10 6 rad, , (d) The wavelength of light has to be decreased, 104., , For a compound microscope, the focal lengths of object lens and eye, lens are fo and fe respectively, then magnification will be done by, microscope when, [RPMT 2001], , 112., , A Galileo telescope has an objective of focal length 100cm and, magnifying power 50. The distance between the two lenses in, normal adjustment will be, , The resolving power of an astronomical telescope is 0.2 seconds. If, the central half portion of the objective lens is covered, the resolving, power will be, [MP PMT 2004], (a) 0.1 sec, , (b) 0.2 sec, , (c) 1.0 sec, , (d) 0.6 sec, , [BHU 2002; Pb. PET 2002], , 105., , (a) 96 cm, , (b) 98 cm, , (c) 102 cm, , (d) 104 cm, , (b) 20, , (a) 2 cm, , (d) 40, , (b) 200 cm, , 1, cm, 2, , (d), , (c) 30, 114., , 1, cm, 200, , (a), (c), , 108., , 109., , 4 10, , 4, , (b) 0.25 10, , rad, , 0.31 10, , 6, , rad, , (d) 5.0 10, , (b) It can detect a very faint radio signal, (c) It can be operated even in cloudy weather, , 6, , 3, , rad, , (d) It is much cheaper than optical telescope, 115., , rad, , (b) 2 cm, , (c) 25 mm, , (d) 0.1 mm, , 116., , In a simple microscope, if the final image is located at infinity then, its magnifying power is, [MP PMT 2004], (a), , 25, f, , (b), , D, 26, , (c), , f, 25, , (d), , f, D 1, , 117., , In a compound microscope the objective of fo and eyepiece of fe, are placed at distance L such that L equals, fo fe, , (b), , fo fe, , (a), , 5.54 10 7 rad, , (b) 2.54 10 4 rad, , (c), , 6.54 10 7 rad, , (d) None of these, , [MP PET 1990], , A telescope has an objective lens of focal length 200 cm and an eye, piece with focal length 2 cm. If this telescope is used to see a 50, meter tall building at a distance of 2 km, what is the height of the, image of the building formed by the objective lens, (a) 5 cm, , (b) 10 cm, , (c) 1 cm, , (d) 2 cm, , Magnification of a compound microscope is 30. Focal length of eyepiece is 5 cm and the image is formed at a distance of distinct vision, of 25 cm. The magnification of the objective lens is, (a) 6, (c) 7.5, , [Kerala PMT 2004], , (a), , The diameter of objective of a telescope is 1m. Its resolving limit for, the light of wave length 4538 Å, will be, [Pb. PET 2003], , A simple magnifying lens is used in such a way that an image is, formed at 25 cm away from the eye. In order to have 10 times, magnification, the focal length of the lens should be, (a) 5 cm, , Which of the following is not correct regarding the radio telescope, (a) It can not work at night, , A telescope of diameter 2m uses light of wavelength 5000 Å for, viewing stars. The minimum angular separation between two stars, whose image is just resolved by this telescope is, [MP PET 2003], , 107., , An astronomical telescope has objective and eye-piece lens of powers, 0.5 D and 20 D respectively, its magnifying power will be, , An astronomical telescope has a magnifying power 10. The focal, (a) 2004], 8, length of eyepiece is 20 cm. The focal length of objective is [MP PMT 2002, 03; Pb. PET, , (c), 106., , 113., , 118., , (b) 5, (d) 10, , At Kavalur in India, the astronomers using a telescope whose, objective had a diameter of one meter started using a telescope of, diameter 2.54 m. This resulted in [KCET 2005]
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(a) The increase in the resolving power by 2.54 times for the same, , (b) The increase in the limiting angle by 2.54 times for the same , , (a) 100 : 1, (c) 1 : 100, 7., , (c) Decrease in resolving power, (d) No effect on the limiting angle, 119., , 120., , A Galileo telescope has an objective of focal length 100 cm and, magnifying power 50. The distance between the two lenses in, normal adjustment will be, [BCECE 2005], (a) 98 cm, , (b) 100 cm, , (c) 150 cm, , (d) 200 cm, , A compound microscope has an eye piece of focal length 10 cm and, an objective of focal length 4 cm. Calculate the magnification, if an, object is kept at a distance of 5 cm from the objective so that final, image is formed at the least distance vision (20 cm), (a) 12, , (b) 11, , (c) 10, , (d) 13, , (b) 10 : 1, (d) 1 : 10, 4, , 4, , A 60 watt bulb is hung over the center of a table 4 m 4 m at a, height of 3 m. The ratio of the intensities of illumination at a point, on the centre of the edge and on the corner of the table is, (a) (17 / 13)3 / 2, , 8., , 9., , (b) 2 / 1, , (c) 17 / 13, (d) 5 / 4, "Lux" is a unit of, (a) Luminous intensity of a source, (b) Illuminance on a surface, (c) Transmission coefficient of a surface, (d) Luminous efficiency of source of light, Total flux, produced by a source of 1 cd is, [UP SEAT 2005], (a), , 1, 4, , (b) 8, , (c), , 4, , (d), , Photometry, 10., 1., , If luminous efficiency of a lamp is 2 lumen/watt and its luminous, intensity is 42 candela, then power of the lamp is, [AFMC 1998], , 2., , 11., , (a) 62 W, , (b) 76 W, , (c) 138 W, , (d) 264 W, , An electric bulb illuminates a plane surface. The intensity of, illumination on the surface at a point 2m away from the bulb is, 5 10 4 phot (lumen/cm ). The line joining the bulb to the point, makes an angle of 60 with the normal to the surface. The intensity, of the bulb in candela is, 2, , o, , 12., , [IIT-JEE 1980; CPMT 1991], , (a), , 40 3, , (c) 20, 3., , (b) 40, (d) 40 10 4, , In a movie hall, the distance between the projector and the screen is, increased by 1% illumination on the screen is, , 4., , 5., , (a) Increased by 1%, , (b) Decreased by 1%, , (c) Increased by 2%, , (d) Decreased by 2%, , Correct exposure for a photographic print is 10 seconds at a distance, of one metre from a point source of 20 candela. For an equal, fogging of the print placed at a distance of 2 m from a 16 candela, source, the necessary time for exposure is, (a) 100 sec, , (b) 25 sec, , (c) 50 sec, , (d) 75 sec, , 14., , 6., , (b), , (c), , 2I0, , (d) 5 5 I0, , 2, , [CPMT 1992], , 15., , 2 5 I0, , A movie projector forms an image 3.5m long of an object 35 mm., Supposing there is negligible absorption of light by aperture then, illuminance on slide and screen will be in the ratio of, , 2, , (a) 80 W, , (b) 176 W, , (c) 88 W, , (d) 36 W, , A lamp rated at 100 cd hangs over the middle of a round table with, diameter 3 m at a height of 2 m. It is replaced by a lamp of 25 cd, and the distance to the table is changed so that the illumination at, the centre of the table remains as before. The illumination at edge of, the table becomes X times the original. Then X is, (a), , 1, 3, , (b), , 16, 27, , (c), , 1, 4, , (d), , 1, 9, , [CPMT 1996], , I0, , (d) 3 : 2, , 2 2 :1, , Lux is equal to, [CPMT 1993], (a) 1 lumen/m, (b) 1 lumen/cm, (c) 1 candela/m, (d) 1 candela/cm, Five lumen/watt is the luminous efficiency of a lamp and its, luminous intensity is 35 candela. The power of the lamp is, 2, , A bulb of 100 watt is hanging at a height of one meter above the, centre of a circular table of diameter 4 m. If the intensity at a point, on its rim is I 0 , then the intensity at the centre of the table will be, (a), , 1, 8, , 2, , [CPMT 1990], , [CPMT 2001], , If the luminous intensity of a 100 W unidirectional bulb is 100, candela, then total luminous flux emitted from the bulb is, (a) 861 lumen, (b) 986 lumen, (c) 1256 lumen, (d) 1561 lumen, The maximum illumination on a screen at a distance of 2 m from a, lamp is 25 lux. The value of total luminous flux emitted by the lamp, is, [JIMPER 1997], (a) 1256 lumen, (b) 1600 lumen, (c) 100 candela, (d) 400 lumen, A small lamp is hung at a height of 8 feet above the centre of a, round table of diameter 16 feet. The ratio of intensities of, illumination at the centre and at points on the circumference of the, table will be, [CPMT 1984, 1996], (a) 1 : 1, (b) 2 : 1, (c), , 13., , [Kerala PMT 2001], , 16., , The distance between a point source of light and a screen which is, 60 cm is increased to 180 cm. The intensity on the screen as, compared with the original intensity will be, [CPMT 1982], , [CPMT 1888], , [
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(a) (1 / 9) times, (c) 3 times, 17., , 25., , (b) (1 / 3) times, (d) 9 times, , A source of light emits a continuous stream of light energy which, falls on a given area. Luminous intensity is defined as, [CPMT 1986], , (a) Luminous energy emitted by the source per second, (b) Luminous flux emitted by source per unit solid angle, , 26., , (c) Luminous flux falling per unit area of a given surface, (d) Luminous flux coming per unit area of an illuminated surface, 18., , Venus looks brighter than other stars because, , [MNR 1985], , (a) It has higher density than other stars, (b) It is closer to the earth than other stars, 27., , (c) It has no atmosphere, (d) Atomic fission takes place on its surface, 19., , To prepare a print the time taken is 5 sec due to lamp of 60 watt at, 0.25 m distance. If the distance is increased to 40 cm then what is, the time taken to prepare the similar print, , 20., , 21., , (b) 1 sec, (d) 16 sec, , 5, (b) , 4, , (c), , 4, 3, , (d), , 4, 5, , 29., , Two stars situated at distances of 1 and 10 light years respectively, from the earth appear to possess the same brightness. The ratio of, their real brightness is, [NCERT 1981], , 22., , 28., , 3, 2, , 1, 2, , (a) 1 : 10, , (b) 10 : 1, , (c) 1 : 100, , (d) 100 : 1, , The intensity of direct sunlight on a surface normal to the rays is, I0 . What is the intensity of direct sunlight on a surface, whose, normal makes an angle of 60 with the rays of the sun, , 30., , 31., , o, , (a), , (c), 23., , 24., , I0, , I0, 2, , (b), , (d), , (b) 0.4 m, , (c) 0.8 m, , (d) 1.6 m, , Two lamps of luminous intensity of 8 Cd and 32 Cd respectively are, lying at a distance of 1.2 m from each other. Where should a screen, be placed between two lamps such that its two faces are equally, illuminated due to two sources, (a) 10 cm from 8 Cd lamp, , (b) 10 cm from 32Cd lamp, , (c) 40 cm from 8 Cd lamp, , (d) 40 cm from 32 Cd lamp, , A lamp is hanging along the axis of a circular table of radius r. At, what height should the lamp be placed above the table, so that the, 1, illuminance at the edge of the table is, of that at its center, 8, , (c), , A lamp is hanging 1 m above the centre of a circular table of, diameter 1m. The ratio of illuminaces at the centre and the edge is, (a), , (a) 0.2 m, , (a), , [CPMT 1982], , (a) 3.1 sec, (c) 12.8 sec, , Two light sources with equal luminous intensity are lying at a, distance of 1.2 m from each other. Where should a screen be placed, between them such that illuminance on one of its faces is four times, that on another face, , 3, , I0 , 2 , , , 2I0, , (b) Cylindrical source, , (c) Search light, , (d) All types of sources, , 1% of light of a source with luminous intensity 50 candela is incident, on a circular surface of radius 10 cm. The average illuminance of, surface is, , (b), , r, 3, , (d), , r, 2, r, 3, , [NCERT 1982], , A point source of 100 candela is held 5m above a sheet of blotting, paper which reflects 75% of light incident upon it. The illuminance, of blotting paper is, (a) 4 phot, (b) 4 lux, (c) 3 phot, (d) 3 lux, A lamp is hanging at a height 40 cm from the centre of a table. If, its height is increased by 10 cm the illuminance on the table will, decrease by, (a) 10 %, (b) 20%, (c) 27%, (d) 36%, Which has more luminous efficiency, (a) A 40 W bulb, (b) A 40 W fluorescent tube, (c) Both have same, (d) Cannot say, An electric lamp is fixed at the ceiling of a circular tunnel as shown, is figure. What is the ratio the intensities of light at base A and a, point B on the wall, S, 1981], (a) 1 : [CPMT, 2, Lamp, Tunnel, , (b) 2 : 3, (c), , 32., , 3 :1, , B, , O, , (d) 1 : 2, A, When sunlight falls normally on earth, a luminous flux of, 1.57 10 5 lumen / m 2 is produced on earth. The distance of, , Inverse square law for illuminance is valid for [CPMT 1978], (a) Isotropic point source, , r, 2, , earth from sun is 1.5 10 8 Km . The luminous intensity of sun in, candela will be, (a), 33., , 3.53 10 27, , (b) 3.53 10 25, , (c) 3.53 10 29, (d) 3.53 10 21, In the above problem, the luminous flux emitted by sun will be, , (a) 100 lux, , (b) 200 lux, , (a), , 4.43 10 25 lm, , (b) 4.43 10 26 lm, , (c) 300 lux, , (d) 400 lux, , (c), , 4.43 10 27 lm, , (d) 4.43 10 28 lm
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34., , A screen receives 3 watt of radiant flux of wavelength 6000 Å. One, lumen is equivalent to 1.5 10 3 watt of monochromatic light of, wavelength 5550 Å. If relative luminosity for 6000 Å is 0.685 while, that for 5550 Å is 1.00, then the luminous flux of the source is, (a), , 35., , 36., , 4 10 3 lm, , (b) 3 10 3 lm, , (c) 2 10 3 lm, (d) 1.37 10 3 lm, A point source of 3000 lumen is located at the centre of a cube of, side length 2m. The flux through one side is, (a) 500 lumen, (b) 600 lumen, (d) 1500 lumen, (c) 750 lumen, Light from a point source falls on a small area placed perpendicular, to the incident light. If the area is rotated about the incident light by, an angle of 60 , by what fraction will the illuminance change, (a) It will be doubled, (b) It will be halved, (c) It will not change, (d) It will become one-fourth, o
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37., , (a), , 1, E, r, , (b), , 3., , 4., , (b) A > C > B, (c) B = C > A, 39., , 40., , (c) 120 (0.6)2 W, , (d) 200W, , Find the luminous intensity of the sun if it produces the same, illuminance on the earth as produced by a bulb of 10000 candela at, a distance 0.3 m. The distance between the sun and the earth is, 1.5 10 11 m, 25 10 22 cd, , (b), , 25 10 18 cd, , (d) 25 10 36 cd, (c) 25 10 26 cd, A lamp is hanging at a height of 4m above a table. The lamp is, lowered by 1m. The percentage increase in illuminace will be, (a) 40 %, (b) 64%, (c) 78%, (d) 92%, , 6., , (d) 3d, 2., , d, , 8., , B, , A, , L, 2L, , Two plane mirrors. A and B are aligned parallel to each other, as, shown in the figure. A light ray is incident at an angle of 30 at a, point just inside one end of A. The plane of incidence coincides with, the plane of the figure. The maximum number of times the ray, undergoes reflections (including the first one) before it emerges out, is, [IIT-JEE (Screening) 2002], , (c), , (d) 100cm, , 0.435cm, , A square of side 3cm is placed at a distance of 25cm from a, concave mirror of focal length 10cm. The centre of the square is at, the axis of the mirror and the plane is normal to the axis. The area, enclosed by the image of the square is, 4cm 2, , (b) 6cm 2, (d) 36cm 2, , A short linear object of length l lies along the axis of a concave, mirror of focal length f at a distance u from the pole of the mirror., The size of the image is approximately equal to [IIT-JEE 1988; BHU 2003; CPMT 20, 1/2, , u, (b) l, f, , f, , , , 2, , 1/2, , f, (d) l, u, , , , f , , 2, , (a), , u, l, f, , f, , , , (c), , f, l, u, , , , f , , A thin rod of length f / 3 lies along the axis of a concave mirror of, , (a), , f, , (b), , 1, f, 2, , (c), , 2f, , (d), , 1, f, 4, , A ray of light falls on the surface of a spherical glass paper weight, making an angle with the normal and is refracted in the medium, at an angle . The angle of deviation of the emergent ray from the, direction of the incident ray, [NCERT 1982], , [IIT-JEE (Screening) 2000], , (a) d/2, , (c) 2d, , (b) 0.87cm, , [MP PET 1995], , A point source of light B is placed at a distance L in front of the, centre of a mirror of width d hung vertically on a wall. A man walks, in front of the mirror along a line parallel to the mirror at a, distance 2L from it as shown. The greatest distance over which he, can see the image of the light source in the mirror is, , (b) d, , (a) 1.74 cm, , focal length f . One end of its magnified image touches an end of, the rod. The length of the image is, , 7., 1., , o, , A, , (c) 16cm 2, 5., , (b) 72W, , 30, , A concave mirror of focal length 100cm is used to obtain the, image of the sun which subtends an angle of 30. The diameter of, the image of the sun will be, , (a), , The relative luminosity of wavelength 600 nm is 0.6. Find the, radiant flux of 600 nm needed to produce the same brightness, sensation as produced by 120 W of radiant flux at 555 nm, , (a), 41., , B, , A, , (a) 50W, , 0.2m, , (d) 34, , 1, E 2, r, , (a) B > C > A, , C, , B, , (c) 32, , E, , (d) B = C < A, , 2 3m, , (b) 30, , 1, 1, (d) E 4, r3, r, Figure shows a glowing mercury tube. The illuminances at point A,, B and C are related as, , (c), 38., , (a) 28, , A point source of light moves in a straight line parallel to a plane, table. Consider a small portion of the table directly below the line of, movement of the source. The illuminance at this portion varies with, its distance r from the source as, , (a), , ( ), , (b) 2( ), , (c), , ( ) / 2, , (d) ( ), , Light enters at an angle of incidence in a transparent rod of, refractive index n. For what value of the refractive index of the, material of the rod the light once entered into it will not leave it, through its lateral face whatsoever be the value of angle of incidence, [CBSE PMT 1998], , 9., , (a), , n 2, , (b) n 1, , (c), , n 1.1, , (d) n 1.3, , A glass hemisphere of radius 0.04 m and R.I. of the material 1.6 is, placed centrally over a cross mark on a paper (i) with the flat face;, (ii) with the curved face in contact with the paper. In each case the
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(a) 16 cm above water level, , cross mark is viewed directly from above. The position of the images, will be, , (b) 9 cm above water level, , [ISM Dhanbad 1994], , (c) 24 cm below water level, , (a) (i) 0.04 m from the flat face; (ii) 0.025 m from the flat face, (b) (i) At the same position of the cross mark; (ii) 0.025 m below, the flat face, , (d) 9 cm below water level, , (c) (i) 0.025 m from the flat face; (ii) 0.04 m from the flat face, , An air bubble in sphere having 4 cm diameter appears 1 cm from, surface nearest to eye when looked along diameter. If = 1.5, the, distance of bubble from refracting surface is, , (d) For both (i) and (ii) 0.025 m from the highest point of the, hemisphere, , (a) 1.2 cm, , (b) 3.2 cm, , (c) 2.8 cm, , (d) 1.6 cm, , 14., , a, , 10., , 11., , One face of a rectangular glass plate 6 cm thick is silvered. An, object held 8 cm in front of the first face, forms an image 12 cm, behind the silvered face. The refractive index of the glass is, (a) 0.4, , (b) 0.8, , (c) 1.2, , (d) 1.6, , [CPMT 2002], , 15., , A rectangular glass slab ABCD, of refractive index n , is immersed in, water of refractive index n (n >n ). A ray of light in incident at the, surface AB of the slab as shown. The maximum value of the angle of, incidence , such that the ray comes out only from the other, surface CD is given by, , An observer, can see through a pin–hole the top end of a thin rod of, [CPMT 1999], height h, placed as shown in the figure. The beaker height is 3h and, its radius h. When the beaker is filled with a liquid up to a height, 2h, he can see the lower end of the rod. Then the refractive index, of the liquid is, , 1, , 2, , 1, , g, , [IIT-JEE (Screening) 2002], , 2, , max, , [IIT-JEE (Screening) 2000], 3h, , D, , A, n1, , max, , n2, , 2h, , C, , B, , 12., , h, , (a), , n, , , , n , 1 , , sin 1 cos sin1 2 (b) sin1 n1 cos sin1, n1 , n 2 , , , , n 2, , (c), , n, sin1 1, n2, , 1, , , , , , , n, (d) sin1 2, n1, , , , , , , A diverging beam of light from a point source S having divergence, angle , falls symmetrically on a glass slab as shown. The angles of, incidence of the two extreme rays are equal. If the thickness of the, glass slab is t and the refractive index n, then the divergence angle, of the emergent beam is, , sin1 (1 / n), , (d), , 2 sin1 (1 / n), , (d) 3/2, , (3 / 2), , A ray of light is incident at the glass–water interface at an angle i, it, emerges finally parallel to the surface of water, then the value of, g would be [IIT-JEE (Screening) 2003], Water r, , (c) 4/3, , Glass, , 17., , A glass prism ( = 1.5) is dipped in water ( = 4/3) as shown in, figure. A light ray is incident normally on the surface AB. It reaches, the surface BC after totally reflected, if, [IIT JEE 1981; MP PMT 1997], , (a) sin 8/9, , B, , (b) 2/3 < sin < 8/9, n, , i, , (d) 1, , i, , i, , w = 4/3, r, , , , (b) , (c), , (c), , (5 / 2), , (b) 1/sin i, , S, , (a) Zero, , (b), , (a) (4/3) sin i, , [IIT-JEE (Screening) 2000], , 13., , 16., , (a) 5/2, , t, , A concave mirror is placed at the bottom of an empty tank with face, upwards and axis vertical. When sunlight falls normally on the mirror,, it is focussed at distance of 32 cm from the mirror. If the tank filled, 4, , with water upto a height of 20 cm, then the sunlight will, 3, , now get focussed at, [UPSEAT 2002], , , , A, , (c) sin 2/3, (d) It is not possible, 18., , C, , A convex lens A of focal length 20 cm and a concave lens B of focal, length 5 cm are kept along the same axis with the distance d, between them. If a parallel beam of light falling on A leaves B as a, parallel beam, then distance d in cm will be, (a) 25, , (b) 15
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(c) 30, 19., , (d) 50, , Diameter of a plano–convex lens is 6 cm and thickness at the centre, is 3 mm. If the speed of light in the material of the lens is 2 10, m/sec, the focal length of the lens is, 8, , (c), , 20., , 21., , (a) 15 cm, , (b) 20 cm, , (c) 30 cm, , (d) 10 cm, , A point object O is placed on the principal axis of a convex lens of, focal length 20 cm at a distance of 40 cm to the left of it. The, diameter of the lens is 10 cm. If the eye is placed 60 cm to the right, of the lens at a distance h below the principal axis, then the, maximum value of h to see the image will be, , 26., , R, , R, , [IIT-JEE (Screening) 2003], , (a) 0, , (b) 5 cm, , (a) 1.25 cm, , (b) 2.5 cm, , (c) 2.5 cm, , (d) 10 cm, , (c) 1.05 cm, , (d) 2 cm, , A luminous object is placed at a distance of 30 cm from the convex, lens of focal length 20 cm. On the other side of the lens, at what, distance from the lens a convex mirror of radius of curvature 10 cm, be placed in order to have an upright image of the object coincident, with it, , 27., , (a) 12 cm, , (b) 30 cm, , (c) 50 cm, , (d) 60 cm, , Shown in the figure here is a convergent lens placed inside a cell, filled with a liquid. The lens has focal length + 20 cm when in air, and its material has refractive index 1.50. If the liquid has refractive, index 1.60, the focal length of the system is [NSEP 1994; DPMT 2000], (a) + 80 cm, , 29., , Liquid, , (b) – 80 cm, (c) – 24 cm, , An achromatic prism is made by crown glass prism ( Ac 19 o ), and flint glass prism ( AF 6 o ) . If C v 1.5 and, then resultant deviation for red coloured ray will be, , 28., , , , The size of the image of an object, which is at infinity, as formed by, a convex lens of focal length 30cm is 2 cm. If a concave lens of, focal length 20 cm is placed between the convex lens and the image, at a distance of 26 cm from the convex lens, calculate the new size, of the image, [MP PMT 1999], , [CBSE PMT 1998; JIPMER 2001, 02], , 22., , (d), R, , [CPMT 1989], , (a) 1.04°, , (b) 5°, , (c) 0.96°, , (d) 13.5°, , F, , v 1.66 ,, , The refracting angle of prism is A and refractive index of material of, A, prism is cot . The angle of minimum deviation is, 2, (a) 180°– 3A, , (b) 180° + 2A, , (c) 90° –A, , (d) 180° – 2A, , An isosceles prism of angle 120° has a refractive index of 1.44. Two, parallel monochromatic rays enter the prism parallel to each other, in air as shown. The rays emerging from the opposite faces, , Lens, , (d) –100 cm, 23., , A hollow double concave lens is made of very thin transparent, material. It can be filled with air or either of two liquids L and L, having refractive indices n and n respectively (n >n >1). The lens will, diverge a parallel beam of light if it is filled with, 1, , 1, , 2, , 2, , 120°, , 2, , 1, , [IIT-JEE, 2000], (a) (Screening), Are parallel, to each other, , (a) Air and placed in air, , (b) Are diverging, , (b) Air and immersed in L, , (c) Make an angle 2 sin1 (0.72) with each other, , 1, , (c) L and immersed in L, 1, , (d) Make an angle 2 {sin1 (0.72) 30 o } with each other, , 2, , (d) L and immersed in L, 2, , 24., , 1, , The object distance u, the image distance v and the magnification m, in a lens follow certain linear relations. These are, (a), , 1, 1, versus, u, v, , (b) m versus u, , (c) u versus v, 25., , 30., , (d) m versus v, , Which one of the following spherical lenses does not exhibit, dispersion? The radii of curvature of the surfaces of the lenses are, as given in the diagrams, [IIT-JEE (Screening) 2002], , 31., (a), , R1, , A ray of light is incident on the hypotenuse of a right-angled prism, after travelling, parallel to the base inside the prism. If is the, [Roorkee 2000], refractive index of the material of the prism, the maximum value of, the base angle for which light is totally reflected from the, hypotenuse is, [EAMCET 2003], , R2, , R1 R2, , (b), , R, , , , (a), , 1, sin1 , , , 1, (b) tan 1 , , , (c), , 1, , sin1 , , , 1, (d) cos 1 , , , The refractive index of the material of the prism and liquid are 1.56, and 1.32 respectively. What will be the value of for the following, refraction, [BHU 2003; CPMT 2004]
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(a), , 13, 11, , sin , , (b) sin , , 11, 13, , sin , , 3, 2, , (c), (d), , sin , , A, , 38., , , , 33., , 34., , (d) All the above, , A small source of light is to be suspended directly above the centre of, a circular table of radius R. What should be the height of the light, source above the table so that the intensity of light is maximum at the, edges of the table compared to any other height of the source, R, 2, , (a) 5 R, , (b) 3 R, , (c) 2 R, , (d) 1.5 R, , (b) 2.0, , (c) 2.5, , (d) 1.5, , 2R, , 3 DPMT, 3, [IIT JEE 1998;, 2000], , (a), , 8, , I0, , P1, , I0, 8, 3, I0, 8, , (b), (c), , P2, P3, 3, 8, A container is filled with water ( = 1.33) upto a height of 33.25 cm., A concave mirror is placed 15 cm above the water level and the, image of an object placed at the bottom is formed 25 cm below the, water level. The focal length of the mirror is, , (d)1997; UPSEAT, I0 1995], [BHU, 40., , (a) 10, (b) 15, , (b) 2C, , (c) 2C, , (d), , A light source is located at P1 as shown in the figure. All sides of, What will be the intensity of illumination at P3, , A ray of light travels from an optically denser to rarer medium. The, critical angle for the two media is C. The maximum possible, deviation of the ray will be, , , C, 2, , , , 2, , the polygon are equal. The intensity of illumination at P2 is I0 ., , A plano-convex lens when silvered in the plane side behaves like a, concave mirror of focal length 30cm. However, when silvered on the, convex side it behaves like a concave mirror of focal length 10 cm., Then the refractive index of its material will be, (a) 3.0, , R, , (b), , (c) R, 39., , [KCET (Engg./Med.) 2002], , 35., , (c) 70 m, , 1, , A spherical surface of radius of curvature R separates air (refractive, index 1.0) from glass (refractive index 1.5). The centre of curvature is, in the glass. A point object P placed in air is found to have a real, image Q in the glass. The line PQ cuts the surface at a point O, and, PO = OQ. The distance PO is equal to, , (a), , (b) 60 m, , (a), , 2, , 32., , (a) 51 m, , 15 cm, , (c) 20, (d) 25, , (d) C, , 41., , An astronaut is looking down on earth's surface from a space, shuttle at an altitude of 400 km . Assuming that the astronaut's, pupil diameter is 5 mm and the wavelength of visible light is, , 33.25 cm, , =1.33, , [MP PMT 1997], , 500 nm. The astronaut will be able to resolve linear object of the, , size of about, , 36., , (c) 50 m, , (d) 500 m, distance, , between, , the, , earth, , (c), and, , moon, , is, , 38.6 10 4 km. The minimum separation between the two points, on the surface of the moon that can be resolved by a telescope, , whose objective lens has a diameter of 5 m with 6000 Å is, , 37., , 5 cm / sec towards the mirror, , (b) 4 cm / sec towards the mirror, , (b) 5 m, , average, , (a), , [AIIMS 2003], , (a) 0.5 m, , The, , 25 cm, , A point object is moving on the principal axis of a concave mirror of, focal length 24 cm towards the mirror. When it is at a distance of, 60cm from the mirror, its velocity is 9 cm / sec. What is the, velocity of the image at that instant, , (a) 5.65 m, , (b) 28.25 m, , (c) 11.30 m, , (d) 56.51 m, , The distance of the moon from earth is 3.8 10 5 km . The eye is, most sensitive to light of wavelength 5500 Å. The separation of two, points on the moon that can be resolved by a 500 cm telescope will, be, [AMU (Med.) 2002], , 4 cm / sec away from the mirror, , (d) 9cm / sec away from the mirror, 42., , A concave mirror is placed on a horizontal table with its axis, directed vertically upwards. Let O be the pole of the mirror and C, its centre of curvature. A point object is placed at C. It has a real, [MP PMT 1993], image, also located at C. If the mirror is now filled with water, the, image will be, [IIT-JEE 1998], (a) Real, and will remain at C, (b) Real, and located at a point between C and , (c) Virtual and located at a point between C and O, (d) Real, and located at a point between C and O, , [
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43., , The diameter of moon is 3.5 10 3 km and its distance from the, earth is 3.8 10 km. If it is seen through a telescope whose focal, length for objective and eye lens are 4 m and 10 cm respectively,, then the angle subtended by the moon on the eye will be, approximately, , (c), , 5, , 50., , (a) 15, , (c) 30, 44., , 45., , o, , (b) 20, , o, , (d) 35, , o, , (d), , A room (cubical) is made of mirrors. An insect is moving along the, diagonal on the floor such that the velocity of image of insect on, two adjacent wall mirrors is 10 cms . The velocity of image of insect, in ceiling mirror is, (a) 10 cms, , (b) 20 cms, , –1, , (c), , The focal length of an objective of a telescope is 3 metre and, diameter 15 cm. Assuming for a normal eye, the diameter of the, pupil is 3 mm for its complete use, the focal length of eye piece, must be, [MP PET 1989], , 10, , –1, , cms, , (d) 10 2 cms, , –1, , –1, , 2, , (a) 6 cm, , (b) 6.3 cm, , Figure shows a cubical room ABCD with the wall CD as a plane, mirror. Each side of the room is 3m. We place a camera at the, midpoint of the wall AB. At what distance should the camera be, focussed to photograph an object placed at A, , (c) 20 cm, , (d) 60 cm, , (a) 1.5 m, , 51., , We wish to see inside an atom. Assuming the atom to have a, diameter of 100 pm, this means that one must be able to resolved a, width of say 10 p.m. If an electron microscope is used, the minimum, electron energy required is about, , A, , (b) 3 m, , 47., , (a) 1.5 KeV, , (b) 15 KeV, , (c) 150 KeV, , (d) 1.5 KeV, , 3m, , (d) More than 6 m, 52., , A telescope has an objective lens of 10 cm diameter and is situated, at a distance of one kilometre from two objects. The minimum, distance between these two objects, which can be resolved by the, telescope, when the mean wavelength of light is 5000 Å, is of the, order of, [CBSE PMT 2004], (a) 0.5 m, , (b) 5 m, , (c) 5 mm, , (d) 5 cm, , (c), , 53., , (a), , x, , (c) 5 m, , , , 49., , A convex lens of focal length 30 cm and a concave lens of 10 cm, focal length are placed so as to have the same axis. If a parallel beam, of light falling on convex lens leaves concave lens as a parallel beam,, then the distance between two lenses will be, , (c) 20 cm, , (d) 10 cm, , A small plane mirror placed at the centre of a spherical screen of, radius R. A beam of light is falling on the mirror. If the mirror, makes n revolution. per second, the speed of light on the screen, after reflection from the mirror will be, (a) 4nR, , (c), , d, , (b) 30 cm, , (b) 2nR, , I, , , , , , , , 2v cos , , , , vO, , vI, x, , A plane mirror is placed at the bottom of the tank containing a, liquid of refractive index . P is a small object at a height h above, the mirror. An observer O-vertically above P outside the liquid see P, and its image in the mirror. The apparent distance between these, two will be, , (b), , (a) 40 cm, , y, , (d) 2v sin, , (a) 6 m, , (d) 1 m, , C, , O, , (b) 2v, , [AIEEE 2005], , 48., , D, , If an object moves towards a plane mirror with a speed v at an, angle to the perpendicular to the plane of the mirror, find the, relative velocity between the object and the image, (a) v, , Two point white dots are 1mm apart on a black paper. They are, viewed by eye of pupil diameter 3 mm. Approximately, what is the, maximum distance at which dots can be resolved by the eye ? [Take, wavelength of light = 500 nm], , (b) 3 m, , B, , (c) 6 m, , [AIIMS 2004], , 46., , nR, 4, , –1, , [NCERT 1982; CPMT 1991], o, , nR, 2, , 2 h, O, , 2h, , , P, , 2h, , 1, , h, , , 1, (d) h 1 , , , , , 54., , One side of a glass slab is silvered as shown. A ray of light is, incident on the other side at angle of incidence i 45 o . Refractive, index of glass is given as 1.5. The deviation of the ray of light from, its initial path when it comes out of the slab is, (a) 90, o, , (b) 180, (c) 120, (d) 45, , o, , o, , 45o, , o, , = 1.5
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55., , 4, , Consider the situation shown in figure. Water w is filled, 3, , in a breaker upto a height of 10 cm. A plane mirror fixed at a height, of 5 cm from the surface of water. Distance of image from the, mirror after reflection from it of an object O at the bottom of the, beaker is, , 61., , 62., , 1.5 cm, , =1.5, 1.5 cm, , 1.5 cm, , A fish rising vertically up towards the surface of water2 cm, with speed 3, P, ms observes a bird diving vertically down towards it with speed 9, ms . The actual velocity of bird is, –1, , (a) 4.5 ms, , –1, , (b) 5. ms, , –1, , –1, , Two transparent slabs have the same thickness as shown. One is, made of material A of refractive index 1.5. The other is made of two, materials B and C with thickness in the ratio 1 : 2. The refractive, index of C is 1.6. If a monochromatic parallel beam passing through, the slabs has the same number of waves inside both, the refractive, index of B is, t/3, , A, , y', , (d) 3.4 ms, , –1, , 63., , 2t/3, , C, , B, , (b) 1.2, , (c) 1.3, (d) 1.4, An object is placed infront of a convex mirror at a distance of 50, cm. A plane mirror is introduced covering the lower half of the, convex mirror. If the distance between the object and plane mirror, is 30 cm, it is found that there is no parallax between the images, formed by two mirrors. Radius of curvature of mirror will be, , 64., , (a) 12.5 cm, , (b) 25 cm, , 65., , 50, cm, 3, , (d) 18 cm, , A beaker containing liquid is placed on a table, underneath a, microscope which can be moved along a vertical scale. The, microscope is focussed, through the liquid onto a mark on the table, when the reading on the scale is a. It is next focussed on the upper, surface of the liquid and the reading is b. More liquid is added and, the observations are repeated, the corresponding readings are c and, d. The refractive index of the liquid is, (a), , d b, d c b a, , (b), , b d, d c b a, , (c), , d c b a, d b, , (d), , d b, ab cd, , Two point light sources are 24 cm apart. Where should a convex, lens of focal length 9 cm be put in between them from one source, so that the images of both the sources are formed at the same place, (a) 6 cm, , (b) 9 cm, , (c) 12 cm, , (d) 15 cm, , There is an equiconvex glass lens with radius of each face as R and, a g 3 / 2 and a w 4 / 3 . If there is water in object space, and air in image space, then the focal length is, , A cube of side 2 m is placed in front of a concave mirror focal, length 1m with its face P at a distance of 3 m and face Q at a, distance of 5 m from the mirror. The distance between the images, of face P and Q and height of images of P and Q are, , 66., , (a) 1 m, 0.5 m, 0.25 m, 2m, , (b) 0.5 m, 1 m, 0.25 m, , y, , (c) 3.0 ms, , (d) 2(u – v), , (a) 1.1, , =1.5, , –1, , A person runs with a speed u towards a bicycle moving away from, him with speed v. The person approaches his image in the mirror, fixed at the rear of bicycle with a speed of, (a) u – v, (b) u – 2v, , (c), , The image of point P when viewed from top of the slabs will be, , (c) 2.0 cm below P, , O, , t, , 59., , 10 cm, , O', , 10, cm, 4, , (c) 2u – v, , 58., , (d) 2 : 1, , (d) 1 cm above P, , (d) 10 cm, , 57., , (c) 1 : 3, (a) 2.0 cm above P, , 5 cm, , (c) 7.5 cm, , 56., , (b) 3 : 1, , (b) 1.5 cm above P, , (a) 15 cm, (b) 12.5 cm, , (a) 1 : 2, , P, , (a) 2R, , (b) R, , (c) 3 R/2, , (d), , R2, , A prism having an apex angle 4 and refraction index 1.5 is located in, front of a vertical plane mirror as shown in figure. Through what, total angle is the ray deviated after reflection from the mirror, o, , (a) 176, , o, , (c) 0.5 m, 0.25 m, 1m, (d) 0.25 m, 1m, 0.5 m, 60., , 2m, , Q, , (b) 4, , 3m, , A small piece of wire bent into an L shape with upright and, horizontal portions of equal lengths, is placed with the horizontal, portion along the axis of the concave mirror whose radius of, curvature is 10 cm. If the bend is 20 cm from the pole of the mirror,, then the ratio of the lengths of the images of the upright and, horizontal portions of the wire is, , o, , (c) 178, (d) 2, 67., , o, , 90°, , 4°, , o, , An optical fibre consists of core of surrounded by a cladding of , < . A beam of light enters from air at an angle with axis of fibre., The highest for which ray can be travelled through fibre is, 1, , 1, , 2
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(a), , 72., , cos1 22 12, 2, , (b) sin1 12 22, (c), , 1, , , , tan 1 12 22, , (d) sec 1 12 22, 68., , 73., , A rod of glass ( = 1.5) and of square cross section is bent into the, shape shown in the figure. A parallel beam of light falls on the plane, flat surface A as shown in the figure. If d is the width of a side and, d, R is the radius of circular arc then for what maximum value of, R, light entering the glass slab through surface A emerges from the, glass through B, , 74., , B, , A compound microscope is used to enlarge an object kept at a, distance 0.03m from it’s objective which consists of several convex, lenses in contact and has focal length 0.02m. If a lens of focal length, 0.1m is removed from the objective, then by what distance the eyepiece of the microscope must be moved to refocus the image, (a) 2.5 cm, , (b) 6 cm, , (c) 15 cm, , (d) 9 cm, , If the focal length of the objective lens and the eye lens are 4 mm, and 25 mm respectively in a compound microscope. The length of, the tube is 16 cm. Find its magnifying power for relaxed eye, position, (a) 32.75, , (b) 327.5, , (c) 0.3275, , (d) None of the above, , Three right angled prisms of refractive indices n1 , n2 and n 3 are, fixed together using an optical glue as shown in figure. If a ray, passes through the prisms without suffering any deviation, then, , (a) 1.5, (b) 0.5, , n2, , d, , (c) 1.3, , n1, , A, , (d) None of these, 69., , R, , The slab of a material of refractive index 2 shown in figure has, curved surface APB of radius of curvature 10 cm and a plane surface, CD. On the left of APB is air and on the right of CD is water with, refractive indices as given in figure. An object O is placed at a, distance of 15 cm from pole P as shown. The distance of the final, image of O from P, as viewed from the left is, (a) 20 cm, , A, , (a), , P, , C', , 75., , C, O, , , , w, , 4, 3, , s= 2.0, B, D of refractive index, A double convex lens, lens made 15ofcma material, cm, refractive, indices 2 and 3 ,, 1 , is placed inside two liquids or 20, , (d) 50 cm, 70., , , , 76., , as shown. 2 1 3 . A wide, parallel beam of light is incident, on the lens from the left. The lens will give rise to, (a) A single convergent, beam, , 77., 2, , 2, 1, , (b) Two different, convergent beams, 3, , (c) Two different, divergent beams, , 3, , (d) A convergent and a divergent beam, 71., , The distance between a convex lens and a plane mirror is 10 cm. The, parallel rays incident on the convex lens after reflection from the, mirror form image at the optical centre of the lens. Focal length of, lens will be, , 78., , (a) 10 cm, (b) 20 cm, (c) 30 cm, (d) Cannot be determined, , O, , n1 n2 n3, , (c) 1 n1 n2 n3, , (b) 30 cm, (c) 40 cm, , n3, , 79., , (b) n1 n2 n3, (d) 1 n22 n12 n32, , In a compound microscope, the focal length of the objective and the, eye lens are 2.5 cm and 5 cm respectively. An object is placed at, 3.75 cm before the objective and image is formed at the least, distance of distinct vision, then the distance between two lenses will, be (i.e. length of the microscopic tube), (a) 11.67 cm, , (b) 12.67 cm, , (c) 13.00 cm, , (d) 12.00 cm, , In a grease spot photometer light from a lamp with dirty chimney is, exactly balanced by a point source distance 10 cm from the grease, spot. On clearing the chimney, the point source is moved 2 cm to, obtain balance again. The percentage of light absorbed by dirty, chimney is nearly, (a) 56%, , (b) 44%, , (c) 36%, , (d) 64%, , The separation between the screen and a plane mirror is 2 r. An, isotropic point source of light is placed exactly midway between the, mirror and the screen. Assume that mirror reflects 100% of incident, light. Then the ratio of illuminances on the screen with and without, the mirror is, (a) 10 : 1, , (b) 2 : 1, , (c) 10 : 9, , (d) 9 : 1, , The separation between the screen and a concave mirror is 2r. An, isotropic point source of light is placed exactly midway between the, mirror and the point source. Mirror has a radius of curvature r and, reflects 100% of the incident light. Then the ratio of illuminances on, the screen with and without the mirror is, (a) 10 : 1, , (b) 2 : 1, , (c) 10 : 9, , (d) 9 : 1, , The apparent depth of water in cylindrical water tank of diameter, 2R cm is reducing at the rate of x cm/minute when water is being
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drained out at a constant rate. The amount of water drained in c.c., per minute is (n = refractive index of air, n = refractive index of, water), [AIIMS 2005], 1, , 2, , (a) x R n /n, , 2, , (b) x R n /n, , (c) 2 R n/n, , 2, , (d) R x, , 2, , 1, , 1, , 2, , 2, , 2, , 1
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(c), , 1., , In an experiment of find the focal length of a concave mirror a, graph is drawn between the magnitudes of u and v. The graph, looks like, [AIIMS 2003], (a) v, , (b), , v, , 6., , u, , u, , (c) v, , 5., , (d) v, , (d), , The graph shows variation of v with change in u for a mirror. Points, plotted above the point P on the curve are for values of v, (a) Smaller then f, v, (b) Smaller then 2f, P, (c) Larger then 2f, (d) Larger than f, m produced by au convex, The graph shows how the magnification 45°, thin lens varies with image distance v. What was the focal length of, the used, [DPMT 1995], b, c, m, b, (b), ca, b, bc, (c), a, a, c, c, v, (d), b, Which of the following graphs shows appropriate variation of, refractive index with wavelength , , (a), , 2., , u, As the position of an object, (u) reflected from a concave umirror is, varied, the position of the image (v) also varies. By letting the u, changes from 0 to the graph between v versus u will be, , (b) v, , (a) v, , u, , u, , 7., (c) v, , (a), , (d) v, u, , 3., , (b), , , , , u, , , (c), , When light is incident on a medium at angle i and refracted into a, second medium at an angle r, the graph of sin i vs sinr is as shown, in the graph. From this, one can conclude that, , , , (d), , , , , , sin r, , 8., , 30o, sin i, , if real image is formed the graph between, For a concave mirror,, , 1, and 1/v is of the form, v, , (a) Velocity of light in the second medium is 1.73 times the velocity, of light in the I medium, , 1/v, , (a), , (b) Velocity of light in the I medium is 1.73 times the velocity in, the II medium, , (b), , (c) The critical angle for the two media is given by, 1/u, , 1, , sin ic , , 1/v, , 3, , 1/v, , (c), (d) sin ic , 4., , 1/u, , (d), , 1, 2, , The graph between the lateral magnification (m) produced by a lens, and the distance of the image (v) is given by, [MP PMT 1994], , 1/u, , 9., , 1/u, , The graph between u and v for a convex mirror is, v, , (a), , m, 0, , (b) m, , v, , m, , 0, , (a), , v, f, , f, , (b), , u, , v, , u, , m, v, , 0, , f, , f, , v, , 0, , f, v, , v, f, , f, , f, , 1, u
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13., , (c), , If x is the distance of an object from the focus of a concave mirror, and y is the distance of image from the focus, then which of the, following graphs is correct between x and y, , (d), (a), , 10., , y, , (b), , x, , For a convex lens, if real image is formed the graph between ( u + v), and u or v is as follows, u+v, , y, , (c), , x, , (d), , y, , y, , u+v, , (a), , (b), 4f, , 4f, , 14., 2f, , 2f, , u or v, , u or v, , x, , x, , For a small angled prism, angle of prism A, the angle of minimum, deviation () varies with the refractive index of the prism as shown, in the graph, Q, , , (c), , u+v, , (d), , (a) Point P corresponds to = 1, , u+v, , (b) Slope of the line PQ = A/2, 4f, , (c) Slope = A, , O, , , , P, , (d) None of the above statements is true, 2f, , u or v, , 11., , u or v, , Which of the following graphs is the magnification of a real image, against the distance from the focus of a concave mirror, y, , 15., , y, , (a), , (b), m, , (a) Total internal reflection can take place, , m, , Distance, , The graph between sine of angle of refraction (sin r) in medium 2, and sine of angle of incidence (sin i) in medium 1 indicates that, 3, (tan 36° ), 4, , x, , Distance, , (b) Total internal reflection, cannot take place, , x, , sin r, , (c) Any of (a) and (b), (d) Data is incomplete, , (c), , y, , (d), , y, , 16., , m, , m, , (a), Distance, , 12., , x, , Distance, , x, , (b), , , , O, y, , (c), , i, , m, , (b) m, , x, , y, , u, , (c), , , , i, , sin i, , For a concave mirror, if virtual image is formed, the graph between, m and u is of the form, , 1, , (d), , , , O, , i, , x, , 30°, –1/2, , (a), O, , –1, , (d) 3, 17., , , , sin r, , 1.5, , (c) 2, , y, , (a), , 2/10, , (b) 2, , A graph is plotted between angle of deviation () and angle of, incidence (i) for a prism. The nearly correct graph is, y, , O, , sin i, A medium shows relation, between i and r as shown. If speed of light in the medium is nc then, value of n is, , f u, , (d) m, , m, 1, , x, O, , i, , x, , u, , u
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18., , A ray of light travels from a medium of refractive index to air. Its, angle of incidence in the medium is i, measured from the normal to, the boundary, and its angle of deviation is . is plotted against i, which of the following best represents the resulting curve, (a) , , 2, , (b) , , 1, , i, , (c), , , 19., , 2, , /2, , O, , (d) 2, , 1, , 1, , /2, , /2, , 7., , : In a movie, ordinarily 24 frames are projected per, second from one end to the other of the complete, film., , Reason, , : The image formed on retina of eye is sustained, upto 1/10 second after the removal of stimulus. [AIIMS 2001], , Assertion, , : Blue colour of sky appears due to scattering of blue, colour., , Reason, , : Blue colour has shortest wave length in visible, spectrum., [AIIMS 2001], , Assertion, , : The refractive index of diamond is, , o, , 1, , where is the refractive index of, sin C, diamond with respect to liquid., [AIIMS 2000], , Reason[BVP 2003], : , , (b), v, , u, , (c), , u, , (d), v, , 8., , Assertion, Reason, , : The setting sun appears to be red., : Scattering of light is directly proportional to the, wavelength., [AIIMS 2000], , 9., , Assertion, , : A double convex lens ( = 1.5) has focal length 10 cm., When the lens is immersed in water ( = 4/3) its, focal length becomes 40 cm., , Reason, , :, , Assertion, , : Different colours travel with different speed in, vacuum., : Wavelength of light depends on refractive index of, medium., [AIIMS 1998], : The colour of the green flower seen through red, glass appears to be dark., : Red glass transmits only red light., , v, , For a convex lens the distance of the object is taken on X-axis and, u, the distance of theu image is taken on Y-axis, the nature of the graph, so obtained is, [BVP 2003], (a) Straight line, , (b) Circle, , (c) Parabola, , (d) Hyperbola, , 6 and that of, , liquid is 3 . If the light travels from diamond to, the liquid, it will totally reflected when the angle of, incidence is 30 ., , /2, , O, , v, , 20., , i, , i real image formed by a convex, i, lens is, The distance v of the, measured for various object distance u. A graph is plotted between v, and u, which one of the following graphs is correct, , (a), , Assertion, , 1, , 2, , O, , : Air bubble in water shines due to refraction of light, [AIIMS 2002], , 5., , 6., O, , Reason, , 10., , Reason, 11., , Assertion, Reason, , 1 l m, , m, f, , 1, 1 , , , R R , 2 , 1, , [AIIMS 1999], , [AIIMS 1997], , Assertion, , : The focal length of the mirror is f and distance of, the object from the focus is u, the magnification of, the mirror is f / u., , Reason, , : Magnification , , 13., , Assertion, , 14., , Reason, Assertion, , : If a plane glass slab is placed on the letters of, different colours all the letters appear to be raised, up to the same height., : Different colours have different wavelengths., : The fluorescent tube is considered better than an, electric bulb., : Efficiency of fluorescent tube is more than the, efficiency of electric bulb., : The polar caps of earth are cold in comparison to, equatorial plane., : The radiation absorbed by polar caps is less than, the radiation absorbed by equatorial plane., : The illumination of earth's surface from sun is more, at noon than in the morning., , 12., Read the assertion and reason carefully to mark the correct option out of, the options given below:, , (a), , (c), (d), (e), , If both assertion and reason are true and the reason is the correct, explanation of the assertion., If both assertion and reason are true but reason is not the correct, explanation of the assertion., If assertion is true but reason is false., If the assertion and reason both are false., If assertion is false but reason is true., , 1., , Assertion, , : A red object appears dark in the yellow light, , Reason, , : A red colour is scattered less, , Assertion, , : The stars twinkle while the planets do not., , Reason, , 15., : The stars are much bigger in size than the planets.[AIIMS 2003], , Assertion, , Assertion, , : Owls can move freely during night., , Reason, , Reason, , : They have large number of rods on their retina.[AIIMS 2003], 16., : The air bubble shines in water., , Assertion, , (b), , 2., , 3., 4., , Assertion, , [AIIMS 2004], , Reason, , Size of image, Size of object, , [AIIMS 1994]
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Reason, 17., , Assertion, , Reason, 18., , Assertion, Reason, , 19., , 20., , Assertion, Reason, Assertion, Reason, , 21., , Assertion, Reason, , 22., , 23., , Assertion, Reason, , : The focal length of a convex mirror is always taken, as positive., , Assertion, , : A piece of red glass is heated till it glows in dark., The colour of glowing glass would be orange., : Red and orange is complementary colours., , Reason, 24., , 25., , 26., , Assertion, , : Within a glass slab, a double convex air bubble is, formed. This air bubble behaves like a converging, lens., , Reason, , : Refractive index of air is more than the refractive, index of glass., , Assertion, , : The images formed by total internal reflections are, much brighter than those formed by mirrors or, lenses., , Reason, , : There is no loss of intensity in total internal, reflection., : The focal length of lens does not change when red, light is replaced by blue light., : The focal length of lens does not depends on colour, of light used., , Assertion, Reason, , 27., , Assertion, Reason, , 28., , Assertion, , Reason, 29., , : Luminance of a surface refers to brightness of the, surface., : When an object is placed between two plane, parallel mirrors, then all the images found are of, equal intensity., : In case of plane parallel mirrors, only two images, are possible., : The mirrors used in search lights are parabolic and, not concave spherical., : In a concave spherical mirror the image formed is, always virtual., : The size of the mirror affect the nature of the, image., : Small mirrors always forms a virtual image., : Just before setting, the sun may appear to be, elliptical. This happens due to refraction., : Refraction of light ray through the atmosphere may, cause different magnification in mutually, perpendicular directions., : Critical angle of light passing from glass to air is, minimum for violet colour., : The wavelength of blue light is greater than the, light of other colours., : We cannot produce a real image by plane or convex, mirrors under any circumstances., , Assertion, Reason, , : There is no dispersion of light refracted through a, rectangular glass slab., : Dispersion of light is the phenomenon of splitting, of a beam of white light into its constituent colours., : All the materials always have the same colour,, whether viewed by reflected light or through, transmitted light., : The colour of material does not depend on nature, of light., : A beam of white light gives a spectrum on passing, through a hollow prism., : Speed of light outside the prism is different from, the speed of light inside the prism., , 30., , Assertion, Reason, , 31., , 32., , 33., , 34., , 35., , 36., , 37., , 38., , 39., , 40., , 41., , Assertion, , : By increasing the diameter of the objective of, telescope, we can increase its range., : The range of a telescope tells us how far away a, star of some standard brightness can be spotted by, telescope., : For the sensitivity of a camera, its aperture should, be reduced., , Reason, , : Smaller the aperture, image focussing is also sharp., , Assertion, , : If objective and eye lenses of a microscope are, interchanged then it can work as telescope., , Reason, , : The objective of telescope has small focal length., , Assertion, , : The illuminance of an image produced by a convex, lens is greater in the middle and less towards the, edges., , Reason, , : The middle part of image is formed by undeflected, rays while outer part by inclined rays., , Assertion, , : Although the surfaces of a goggle lens are curved, it, does not have any power., , Reason, , : In case of goggles, both the curved surfaces have, equal radii of curvature., , Assertion, , : The resolving power of an electron microscope is, higher than that of an optical microscope., , Reason, , : The wavelength of electron is more than the, wavelength of visible light., , Assertion, , : If the angles of the base of the prism are equal,, then in the position of minimum deviation, the, refracted ray will pass parallel to the base of prism., , Reason, , : In the case of minimum deviation, the angle of, incidence is equal to the angle of emergence., , Assertion, , : Dispersion of light occurs because velocity of light, in a material depends upon its colour., , Reason, , : The dispersive power depends only upon the, material of the prism, not upon the refracting angle, of the prism., , Assertion, , : An empty test tube dipped into water in a beaker, appears silver, when viewed from a suitable, direction., , Reason, , : Due to refraction of light, the substance in water, appears silvery., , Assertion, , : Spherical aberration occur in lenses of larger, aperture., , Reason, , : The two rays, paraxial and marginal rays focus at, different points., , Assertion, , : It is impossible to photograph a virtual image., , Reason, , : The rays which appear diverging from a virtual, image fall on the camera and a real image is, captured., , Assertion, , : The speed of light in a rarer medium is greater, than that in a denser medium, , Reason, , : One light year equals to 9.5 × 10 km, , Assertion, , : The frequencies of incident, reflected and refracted, beam of monochromatic light incident from one, medium to another are same, , 12, , [AIIMS 1999], , 42.
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43., , Reason, , : The incident, reflected and refracted rays are, coplanar, [EAMCET (Engg.) 2000], , 1, , d, , 2, , a, , 3, , b, , 4, , a, , 5, , d, , Assertion, , : The refractive index of a prism depends only on the, kind of glass of which it is made of and the colour, of light, , 6, , a, , 7, , c, , 8, , d, , 9, , c, , 10, , a, , 11, , b, , 12, , d, , 13, , b, , 14, , a, , 15, , b, , : The refractive index of a prism depends upon the, refracting angle of the prism and the angle of, minimum deviation, [AIIMS 2000], , 16, , a, , 17, , c, , 18, , c, , 19, , d, , 20, , a, , 21, , b, , 22, , b, , 23, , c, , 24, , a, , 25, , c, , 26, , a, , 27, , b, , 28, , d, , 29, , a, , 30, , c, , 31, , c, , 32, , c, , 33, , b, , 34, , b, , 35, , b, , b, , 37, , a, , 38, , b, , 39, , c, , 40, , d, , 41, , a, , 42, , d, , 43, , c, , 44, , c, , 45, , a, , 46, , Reason, , 44., , 45., , 46., , Assertion, , : The resolving power of a telescope is more if the, diameter of the objective lens is more., , Reason, , 36, : Objective lens of large diameter collects more light.[AIIMS 2005], , Assertion, , : By roughening the surface of a glass sheet its, transparency can be reduced., , a, , 47, , c, , 48, , a, , 49, , c, , 50, , c, , Reason, , : Glass sheet with rough surface absorbs more light.[AIIMS 2005], 51, , d, , 52, , b, , 53, , b, , 54, , b, , 55, , b, , Assertion, , : Diamond glitters brilliantly., , 56, , a, , 57, , d, , 58, , b, , 59, , c, , 60, , b, , Reason, , : Diamond does not absorb sunlight., , 61, , d, , 62, , a, , 63, , b, , 64, , d, , 65, , b, , 66, , a, , 67, , b, , 68, , b, , 69, , a, , 70, , d, , 71, , c, , 72, , c, , 73, , d, , 74, , d, , 75, , b, , 76, , d, , 77, , c, , 78, , c, , 79, , b, , 80, , b, , 81, , a, , 82, , a, , 83, , b, , 84, , b, , 85, , c, , 86, , b, , 87, , d, , 88, , d, , 89, , b, , 90, , d, , [AIIMS 2005], , 47., , Assertion, , : The cloud in sky generally appear to be whitish., , Reason, , : Diffraction due to cloud is efficient in equal, measure at all wavelengths., [AIIMS 2005], , Total Internal Reflection, Plane Mirror, , 1, , b, , 2, , c, , 3, , d, , 4, , d, , 5, , c, , 6, , c, , 7, , b, , 8, , c, , 9, , a, , 10, , d, , 11, , b, , 12, , c, , 13, , c, , 14, , d, , 15, , d, , 16, , c, , 17, , c, , 18, , cd, , 19, , c, , 20, , d, , 21, , a, , 22, , c, , 23, , b, , 24, , c, , 25, , a, , 1, , d, , 2, , b, , 3, , b, , 4, , c,d, , 5, , c, , 6, , c, , 7, , d, , 8, , b, , 9, , b, , 10, , c, , 11, , b, , 12, , d, , 13, , a, , 14, , c, , 15, , c, , 26, , c, , 27, , c, , 28, , a, , 29, , d, , 30, , d, , 16, , b, , 17, , c, , 18, , b, , 19, , c, , 20, , a, , 31, , a, , 32, , c, , 33, , a, , 34, , c, , 35, , a, , 21, , c, , 22, , b, , 23, , c, , 24, , b, , 25, , b, , 36, , d, , 37, , b, , 38, , b, , 39, , c, , 40, , a, , 26, , b, , 27, , c, , 28, , c, , 29, , c, , 30, , c, , 41, , c, , 42, , b, , 43, , b, , 44, , d, , 45, , B, , 31, , b, , 32, , a, , 33, , b, , 34, , c, , 46, , a, , Refraction at Curved Surface, , Spherical Mirror, 1, , a, , 2, , a, , 3, , d, , 4, , c, , 5, , a, , 6, , d, , 7, , b, , 8, , a, , 9, , c, , 10, , c, , b, , 11, , c, , 12, , d, , 13, , b, , 14, , c, , 15, , b, , 15, , c, , 16, , d, , 17, , c, , 18, , d, , 19, , c, , 20, , c, , a, , 20, , a, , 21, , c, , 22, , a, , 23, , d, , 24, , a, , 25, , d, , 24, , d, , 25, , b, , 26, , a, , 27, , b, , 28, , a, , 29, , a, , 30, , c, , 29, , a, , 30, , b, , 31, , c, , 32, , d, , 33, , d, , 34, , c, , 35, , b, , b, , 37, , c, , 38, , d, , 39, , b, , 40, , d, , 1, , a, , 2, , c, , 3, , d, , 4, , c, , 5, , a, , 6, , b, , 7, , c, , 8, , b, , 9, , a, , 10, , 11, , d, , 12, , b, , 13, , b, , 14, , b, , 16, , d, , 17, , b, , 18, , b, , 19, , 21, , a, , 22, , b, , 23, , d, , 26, , bc, , 27, , c, , 28, , b, , 31, , d, , 32, , c, , 33, , a, , 34, , d, , 35, , d, , 36, , 36, , b, , 37, , d, , 38, , d, , 39, , d, , 40, , a, , 41, , a, , 42, , c, , 43, , a, , 44, , c, , 45, , d, , 46, , d, , 47, , c, , 48, , b, , 49, , a, , 50, , b, , 51, , c, , 52, , a, , 53, , a, , 54, , b, , 55, , a, , 41, , d, , 42, , d, , 43, , a, , 44, , a, , Refraction of Light at Plane Surfaces
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56, , b, , 57, , a, , 58, , a, , 59, , d, , 60, , c, , 131, , a, , 132, , c, , 133, , a, , 134, , c, , 135, , b, , 61, , b, , 62, , b, , 63, , d, , 64, , d, , 65, , d, , 136, , c, , 137, , a, , 138, , d, , 139, , c, , 140, , b, , 66, , a, , 67, , d, , 68, , c, , 69, , c, , 70, , b, , 141, , a, , 142, , a, , 143, , b, , 144, , b, , 145, , a, , 71, , d, , 72, , b, , 73, , a, , 74, , c, , 75, , a, , 146, , a, , 147, , d, , 148, , b, , 149, , c, , 150, , a, , 76, , c, , 77, , a, , 78, , b, , 79, , b, , 80, , d, , 151, , c, , 81, , c, , 82, , a, , 83, , d, , 84, , a, , 85, , c, , 86, , c, , 87, , b, , 88, , a, , 89, , a, , 90, , b, , 91, , b, , 92, , d, , 93, , c, , 94, , a, , 95, , c, , 96, , c, , 97, , c, , 98, , a, , 99, , d, , 100, , a, , 101, , a, , 102, , d, , 103, , c, , 104, , d, , 105, , a, , 106, , c, , 107, , b, , 108, , a, , 109, , d, , 110, , b, , 111, , c, , 112, , c, , 113, , c, , 114, , d, , 115, , a, , 116, , c, , 117, , a, , 118, , d, , 119, , c, , 120, , b, , 121, , c, , 122, , d, , 123, , a, , 124, , b, , 125, , d, , 126, , c, , 127, , d, , 128, , b, , 129, , b, , 130, , c, , 131, , b, , 132, , b, , 133, , b, , 134, , d, , 135, , b, , 136, , d, , 137, , d, , 138, , b, , 139, , a, , 140, , c, , 141, , b, , 142, , b, , 143, , c, , 144, , b, , 145, , c, , Prism Theory & Dispersion of Light, 1, , b, , 2, , b, , 3, , b, , 4, , c, , 5, , c, , 6, , a, , 7, , a, , 8, , d, , 9, , d, , 10, , d, , 11, , c, , 12, , b, , 13, , b, , 14, , a, , 15, , a, , 16, , b, , 17, , d, , 18, , a, , 19, , d, , 20, , b, , Human Eye and Lens Camera, 1, , c, , 2, , a, , 3, , b, , 4, , d, , 5, , b, , 6, , c, , 7, , b, , 8, , a, , 9, , d, , 10, , a, , 11, , c, , 12, , c, , 13, , a, , 14, , b, , 15, , d, , 16, , b, , 17, , c, , 18, , c, , 19, , b, , 20, , c, , 21, , b, , 22, , a, , 23, , a, , 24, , a, , 25, , d, , 26, , a, , 27, , d, , 28, , c, , 29, , b, , 30, , c, , 31, , c, , 32, , c, , 33, , b, , 34, , b, , 35, , a, , 36, , c, , 37, , d, , 38, , a, , 39, , d, , 40, , a, , 41, , b, , 42, , c, , 43, , d, , 44, , a, , 45, , b, , 46, , b, , 47, , d, , 48, , d, , 49, , b, , 50, , b, , 51, , c, , 52, , a, , 53, , a, , 54, , c, , 55, , d, , 56, , a, , 57, , a, , 58, , d, , 59, , a, , 60, , d, , 61, , d, , 62, , a, , 63, , b, , 64, , d, , 65, , a, , Microscope and Telescope, 1, , c, , 2, , b, , 3, , b, , 4, , b, , 5, , b, , 6, , d, , 7, , c, , 8, , a, , 9, , b, , 10, , b, , 11, , a, , 12, , b, , 13, , b, , 14, , a, , 15, , c, , 21, , a, , 22, , c, , 23, , a, , 24, , a, , 25, , b, , 26, , c, , 27, , c, , 28, , b, , 29, , a, , 30, , a, , 31, , c, , 32, , b, , 33, , a, , 34, , c, , 35, , d, , 16, , d, , 17, , a, , 18, , b, , 19, , b, , 20, , b, , 36, , a, , 37, , b, , 38, , a, , 39, , d, , 40, , b, , 21, , a, , 22, , d, , 23, , c, , 24, , a, , 25, , d, , c, , 27, , c, , 28, , d, , 29, , d, , 30, , b, , 41, , b, , 42, , b, , 43, , a, , 44, , c, , 45, , a, , 26, , 46, , c, , 47, , b, , 48, , a, , 49, , c, , 50, , c, , 31, , a, , 32, , d, , 33, , d, , 34, , c, , 35, , d, , 51, , c, , 52, , a, , 53, , d, , 54, , d, , 55, , a, , 36, , b, , 37, , a, , 38, , a, , 39, , b, , 40, , d, , 56, , c, , 57, , a, , 58, , a, , 59, , a, , 60, , c, , 41, , d, , 42, , b, , 43, , d, , 44, , a, , 45, , c, , 61, , c, , 62, , b, , 63, , d, , 64, , d, , 65, , a, , 46, , b, , 47, , b, , 48, , d, , 49, , b, , 50, , d, , 66, , b, , 67, , c, , 68, , c, , 69, , b, , 70, , c, , 51, , c, , 52, , a, , 53, , a, , 54, , a, , 55, , b, , 71, , a, , 72, , d, , 73, , a, , 74, , b, , 75, , a, , 56, , a, , 57, , d, , 58, , d, , 59, , c, , 60, , c, , 76, , b, , 77, , b, , 78, , b, , 79, , d, , 80, , a, , 61, , c, , 62, , a, , 63, , b, , 64, , a, , 65, , b, , 81, , b, , 82, , a, , 83, , b, , 84, , c, , 85, , a, , 66, , a, , 67, , a, , 68, , c, , 69, , a, , 70, , b, , 86, , c, , 87, , c, , 88, , a, , 89, , b, , 90, , b, , 71, , c, , 72, , b, , 73, , a, , 74, , a, , 75, , b, , 91, , c, , 92, , a, , 93, , c, , 94, , c, , 95, , b, , 76, , d, , 77, , c, , 78, , b, , 79, , a, , 80, , c, , 96, , c, , 97, , c, , 98, , a, , 99, , a, , 100, , c, , 81, , b, , 82, , b, , 83, , b, , 84, , a, , 85, , b, , 101, , a, , 102, , b, , 103, , a, , 104, , b, , 105, , d, , 86, , abcd, , 87, , a, , 88, , a, , 89, , b, , 90, , c, , 106, , b, , 107, , b, , 108, , a, , 109, , b, , 110, , a, , 91, , b, , 92, , d, , 93, , c, , 94, , d, , 95, , c, , 111, , a, , 112, , d, , 113, , a, , 114, , b, , 115, , a, , 96, , c, , 97, , d, , 98, , a, , 99, , b, , 100, , d, , 116, , d, , 117, , d, , 118, , d, , 119, , c, , 120, , d, , 101, , c, , 102, , b, , 103, , a, , 104, , b, , 105, , b, , 121, , a, , 122, , d, , 123, , c, , 124, , d, , 125, , b, , 106, , c, , 107, , c, , 108, , a, , 109, , c, , 110, , c, , 126, , a, , 127, , c, , 128, , c, , 129, , d, , 130, , a, , 111, , d, , 112, , a, , 113, , d, , 114, , a, , 115, , a
