Question 1 :
The power of a lens whose focal length is one metre is ______ dioptre.
Question 2 :
During refraction through a glass block, the angle of refraction _______.
Question 3 :
Ray optics fail when the size of the obstacle is :
Question 4 :
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
Question 8 :
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 imagebecomes inverted. What type of mirror he is using
Question 9 :
If $f$ is the focal length of a lens, then the power of the lens is equal to
Question 10 :
Which of the following term is not associated with a lens ?
Question 11 :
State whether true or false.<br/>The images formed by a convex mirror are always erect and enlarged.
Question 12 :
In case of a real and inverted image, the magnification created by the mirror is<br/>
Question 13 :
A ray of light is incident normally on a plane glass slab. What will be the angle of refraction ?
Question 15 :
A ray of light is incident perpendicularly on a glass slab. The angle of incidence is :
Question 16 :
The radii of curvature of both the sides of a convex lens are $15cm$ and if the refractive index of material of the lens is $1.5$. Then focal length of lens in air is _______cm.
Question 17 :
State whether true or false : The degree of convergence of divergence of light rays achieved by a lens is expressed in terms of its power.
Question 18 :
Fill in the blank. A _____ is a piece of transparent glass bounded by two spherical surfaces. 
Question 20 :
A light ray travels at some angle (not head on) from water in a rectangular aquarium, through the glass side, and out into air . The indices if refraction for water, glass, and air are 1.33, about 1.6, and 1.0, respectively.<br/>Rank the material;s according to the angles of refraction  made by the light ray with the normal in each, greatest first.
Question 21 :
No matter how far you stand from a mirror, your image appears erect. The mirror is likely to be<br>
Question 22 :
A ray of light is incident on the surface of transparent medium at an angle of $45^o$ and is refracted in the medium at an angle of $30^o$. What will be the velocity of light in the transparent medium ? <br/>
Question 23 :
Choose the correct statement(s) related to the motion of object and its image in the case of  mirrors.
Question 25 :
What is the angle of incidence when a ray of light incident on a concave mirror from its centre of curvature?
Question 28 :
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
Question 29 :
To construct a ray diagram, you need a minimum of  _______ ray(s) whose path(s) after refraction through the lens are known.
Question 30 :
If the refractive index of medium $b$ with respect to medium $a$ and that of medium $c$ with respect to medium b are given, then the refractive index of a medium $c$ with respect to a medium $a$ can be found by using the relation<br/>$n_{ca}\, =\, n_{ba}\, \times\, ........$<br/><br/>
Question 32 :
Ratio of the size of the image to the size of the object is known as:
Question 34 :
The heat of sun focussed by a convex lens on a piece of paper is capable of
Question 35 :
The mirror which always produces an erect and virtual image of a real object is:<br/>
Question 36 :
The magnification of an image by a convex lens is positive only when the project is placed:
Question 37 :
When light goes from a denser to a rarer medium the angle of refraction is:
Question 38 :
In case of a virtual and erect image, the magnification created by the mirror is
Question 39 :
The power of a lens is negative. State whether it is convex or concave?<br/>
Question 40 :
State the direction of incident ray which after reflection from a spherical mirror retraces its path:
Question 42 :
The focal length of a convex mirror is $20\ cm$ its radius of curvature will be
Question 45 :
A virtual image larger than the object can be produced by a
Question 47 :
Due to refraction, when seen from outside,a coin placed under water in a bowl, appears to
Question 50 :
A concave mirror of focal length $f$ (in air) is immersed in water $(\mu=4/3).$ The focal length of the mirror in water will be
Question 51 :
Light ray that strikes surface of a glass slab normally. Will it deviate from its path? Yes or No<br/>
Question 52 :
A concave lens always gives a virtual image. In opticallenses worn by humans which of the following statementsis true ?
Question 53 :
A large rectangular glass slab has two sets of parallel faces. Light ray is incident on the glass slab and trace of light ray is drawn. Now glass slab is rotated by $90^o$ such that light ray now passes to second set of parallel faces. What will be the effect on trace of light?
Question 54 :
Calculate the magnification of an object if it is kept at a distance of $3 cm$ from a concave mirror of focal length $4 cm$:
Question 55 :
A ray of light in a liquid of refractive index 1.4, approaches the boundary surface between the liquid and air at an angle of incidence whose sine is 0.8. Which of the following statements is correct about the behaviour of the light
Question 56 :
It is desired to produce a real image on a screen using a convex lens of focal length 10 cm. The minimum distance between the object and the screen should be then<br/>
Question 57 :
A glass slab has two long parallel faces. Light ray is incident on the glass slab and trace of light ray is drawn. Now glass slab is shifted parallel to the parallel faces. What will be the effect on the trace of light?
Question 58 :
When light passes from one medium to another, the physical quantity that remains unchanged is
Question 59 :
An object is placed on the principal axis of a concave mirror at a distance of 60 cm. If the focal length of the concave mirror is 40 cm then the magnification obtained is equal to:
Question 60 :
Images formed by which of the following arrangement isnot Virtual and erect ?
Question 61 :
A ray of light travelling inside a rectangular glass block of refractive index $\sqrt 2$ is incident on the glass-air interface at an angle of incidence of $45^o$. The refractive index of air is one. Under the these conditions the ray will
Question 62 :
For the same angle of incidence, the angles of refraction in media P, Q, R and S are $50^o, 40^o, 30^o, 20^o$, respectively. The speed of light is minimum in medium :<br/>
Question 63 :
A student performs an experiment to study the nature of the image formed by a convex lens. <br/>Arrange the steps in the proper sequence.<br/>(a) Place the lens on a V-shaped stand.<br/>(b) Place the object at $2F_{1}$.<br/>(c) Place the object between $2F_{1}$ and $F_{1}$.<br/>(d) Determine the focal length of the lens by focusing the lens to a distant object like a tree.<br/>(e) Adjust the position of the screen behind the lens to obtain a clear image and study the nature of the image.<br/>(f) Mark the positions of $F_{1}, 2F_{1}, F_{2}$   and $ 2F_{2}$.<br/>(g) Focus the lens to a distant object like a tree.<br/>(h) Place the object just behind $2F_{1}$.<br/>(i) Place the object at $F_{1}$.<br/>(j) Place the object between $F_{1}$ and optic centre of the lens and observe that the image formed is virtual.<br/>
Question 65 :
A concave mirror produces $2$ times magnified real image of an object placed at $5 cm$ in front of it. Where is image located?
Question 66 :
Identify the power of the lens in increasing order for the following cases<br/>1) lens of focal length 10 cm<br/>2) lens of focal length 10 m<br/>3) lens of focal length 2 m<br/>4) lens of focal length 50 m
Question 67 :
A straight line graph is obtained by plotting sine of angle of incidence versus sine of angle of refraction. The slope of this graph represents :
Question 68 :
If the angle of incidence is i and that of refraction is r. Then the speed of light in the medium to which the light is reflected from air is?
Question 69 :
A monochromatic ray of light enters a glass slab $\left( n=1.5 \right) $ along the normal to the surface. The angle of deviation of the refracted ray is:
Question 70 :
A ray of light is incident from one medium $(\mu = 1.5)$ into another medium. If the angle of incidence and refraction are, respectively,$60$and$45$, thenwhatwill be the refractive index of the denser medium?
Question 71 :
A ray of light travelling in a transparent medium falls on a surface separating the medium from air at an angle of incidence of $45^{o}$. 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:
Question 72 :
The magnification produced by a mirror is $+\dfrac{1}{3}.$ Then the mirror is a ____________.
Question 73 :
If a lens has power -2.5D, then it is a :
Question 74 :
A thin layer of water is transparent but a very thick layer of water is
Question 75 :
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:-
Question 76 :
The angle between reflected and refracted beams is $90^0$in the water air interface. The angle of incidence in water is
Question 78 :
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 to be formed to form the image of an object. At what distance from this lens, an object is to be placed in order to have a real image of the size of the object?
Question 79 :
A ray of light is incident on glass slab making an angle of incidence $sin^{-1} \left( \dfrac{\sqrt 3}{2} \right )$. What will be the angle of refraction in glass of refractive index 1.5?
Question 80 :
The distance between an object and a divergent lens is $m$ times the focal length of the lens. The linear magnification produced by the lens is
Question 81 :
The radius of curvature of a plano-convex lens  is 20 cm If the refractive index of the material of the lens be 1.5 it will
Question 82 :
What does the sign of magnification indicates $\left (m = \dfrac {-v}{u}\right )$?<br/>a) Negative sign indicates image is real and inverted.<br/>b) Positive sign indicates image is erect and virtual.<br/>c) Positive sign indicates image is virtual.
Question 83 :
A light ray travels from optically denser medium to optically rarer medium, if the angle of incidence and refraction at point of incidence are $\angle i$ and $\angle r$ respectively, then find the angle of deviation in terms of $\angle i$ and $\angle r$.
Question 84 :
An object is placed on the principal axis of a concave mirror at a distance of 60 cm. If thefocal length of the concave mirror is 40 cm then determine the magnification of the obtainedimage.
Question 86 :
Assertion: Thinner lenses have smaller power.
Reason: Power is directly proportional to the focal length
Question 87 :
A square card of side length 1 mm is being seen through a magnifying lens of focal length 10 cm. The card is placed at a distance of 9 cm from the lens. The apparent area of the card through the lens is
Question 88 :
The frequency of a light wave in a material is $2\times 10^{14}$Hz and wavelength is $5000\overset{o}{A}$. The refractive index of material will be
Question 89 :
The linear magnification for a spherical mirror is the ratio of the size of the image to the size of the object, and is denoted by m. Then m is equal to (symbols have their usual meanings)
Question 90 :
A convex lens of focal length 80 cm and concave lens of focal length 50 cm are combined together. What will be their resultant power?<br>
Question 91 :
A point on the principal axis of a lens, to which light rays parallel to the principal axis converge after passing through the lens, is ............
Question 92 :
In optical instruments, the lenses are used to form image by the phenomenon of
Question 93 :
A beam of monochromatic blue light of wavelength $4200\mathring { A } $ in air travels in water of refractive index ${ 4 }/{ 3 }$. Its wavelength in water will be
Question 95 :
What would you use to obtain  a virtual and erect image?
Question 96 :
An object $15 cm$ high is placed $10 cm$ from the optical center of a thin lens. Its image is formed $25 cm$ from the optical center on the same side of the lens as the object. The height of the image is:<br>
Question 97 :
A real object is placed at a distance $\dfrac{f}{2}$ in front of a concave mirror having focal length $f$. If object is shifted by a distance $\dfrac{f}{4}$ away from the mirror. Find the ratio of final magnification to initial magnification.
Question 98 :
A red colour in air has wavelength 760 nm when light passes through water of refractive index $\left( n=\frac { 4 }{ 3 } \right) $, wavelength becomes 570 nm.(wavelength of yellow colour in air is 570 nm).Then colour of red light in water is
Question 99 :
Two power of a converging lens is 4 D and that of a diverging lens is 2.5D.The power of this combination of lenses placed closed together is:
Question 100 : <p>One face of a rectangular glass plate$6{\text{ }}cm$ thick is silvered. An object held$8{\text{ }}cm$ in front of the fist face, forms an image$12{\text{ }}cm$ behind the silvered face. The refractive index of the glass is:</p>
Question 101 :
A spherical convex surface separates object and image space of refractive index $1$ and $4/3$ respectively. If radius of curvature of the surface s $0.1\ m$, its power is
Question 102 :
A water film is formed on a glass-block. A light ray is incident on water film from air at an angle of$\displaystyle { 60 }^{ \circ }$ with the normal. The angle of incidence on glass slab is<br>($\displaystyle { \mu }_{ g } = 1.5,{ \mu }_{ w } = \frac { 4 }{ 3 }$)
Question 103 :
When a light of wavelength $4000$ $\displaystyle \overset { \circ  }{ A } $ in vacuum travels through the same thickness in diamond and water separately, the difference in the number of waves is $200$. Find the thickness, if refractive indices of diamond and water are $\displaystyle \frac { 5 }{ 2 } $ and $\displaystyle \frac { 4 }{ 3 } $ respectively.
Question 104 :
A ray of light going towards the centre of curvature of a convex mirror ............
Question 105 : In the table below, column I lists various mirrors  and lenses and column II their uses, qualities or properties.<br/><table class="wysiwyg-table"><tbody><tr><td>column  I</td><td>Column II</td></tr><tr><td>I. Plane mirror</td><td>A. Feels thinner in the middle.</td></tr><tr><td>II. Concave mirror</td><td>B. Always forms virtual image.</td></tr><tr><td>III. Convex mirror</td><td>C. Always forms virtual image of smaller size.</td></tr><tr><td>IV. Concave lens </td><td>D. Is used by dentists to examine teeth.</td></tr><tr><td>V. Convex lens</td><td>E. Can be used as reading glass.<br/></td></tr></tbody></table>The correct matching is:
Question 106 :
A $2.5$ dioptre lens forms a virtual image which is $4$ times the object placed perpendicularly on the lens. Then the required distance of the object from the lens is .
Question 107 :
A short linear object of length $b$ 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 :<br>
Question 108 :
Image of an object at infinity is formed by a convex lens of focal length $30 \ cm$ such that the size of the image is $2 \ cm$. If a concave lens of focal length $20\  cm$ is placed in between the convex lens and the image, at a distance $26\  cm$ from the convex lens, size of the new image is:
Question 109 :
A $4.5 cm$ needle is placed $12 cm$ away from a convex mirror of focal length $15 cm$. Find the location of the image and the magnification.
Question 110 :
A point object is placed on the principal axis of the convex lens of focal length 20cm at a distance 40 cm to the left on it. The diameter of the lens is 10cm. If the eye is placed 60cm to the right of the lens at a distance h below the principal axis, then max value of 'h' to see the image is
Question 111 :
A short linear object of length $b$ 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:<br/>
Question 112 :
A small object of linear dimension $x$ lies on the axis of an optical mirror of local length $f$ at a distance $a$ from mirror. The linear dimension of image:
Question 113 :
Air has refractive index $1.0003$. Find the thickness of air column which will contain one more wavelength of yellow light of $6000$ $A^0$ than in same thickness of vacuum.
Question 114 :
The glancing angle of incidence is $10^{\circ}$. What will be the glancing angle of reflection?
Question 115 :
What happens when a ray of light is made to fall on a mirror along the normal?<br/>
Question 116 :
The focal length of a thin biconvex lens is 20 cm. when an object is moved from a distance of 25 cm in front of it to 50 cm, the magnification of its image changes from $m_{25}$ to $m_{50}$. The ratio of $m_{25}$ to $m_{50}$ is :
Question 117 :
In vacuum, to travel distance 'd', light takes time 't' and in medium to travel distance $'5d'$, it takes time 'T'. The critical angle of the medium is.<br>
Question 118 :
An object is placed at $30$ cm distance from a concave mirror of focal length $20$ cm, then nature, magnification of the image will be:
Question 119 :
The distance between an object and its doubly magnified image by a concave mirror is: [ Assume $f$ = focal length]
Question 120 :
The angle between the incident ray and the normal is called ________.<br>
Question 121 :
The magnitude of focal length of a concave mirror is $f$. An object is placed at a distance $x$ from the focus and forms a real image. The magnification is:<br/>
Question 122 :
The image obtained while finding the focal length of convex lens is...................
Question 123 :
The diameter of the reflecting surface of spherical mirror is called ..............
Question 124 :
A concave shaving mirror has a radius of curvature of 35.0 cm. It is positioned so that the (upright) image of a mans face is 2.50 times the size of the face. How far is the mirror from the face?
Question 126 :
An image of a bright square is obtained on a screen with the aid of a convergent lens. The distance between the square and the lens is $40\ cm$. The area of the image is nine times larger than that of the square. Select the correct statement(s).
Question 127 :
Aconvex lens of radii of curvature 20 cm and 30 cm respectively. It is silveredat the surface which has smaller radius of curvature. Then it will behave as $(\mu_g\, = \, 1.5)$
Question 128 :
Three convex lenses are available having focal lengths of $4 cm, 40 cm$ and $4 m$ respectively. Which one could be used as magnifying glass?
Question 129 :
A flim projector magnifies a flim of area $100 $ square centimeter on screen. If linear magnification is $4$ then area of magnified image on screen will be-
Question 130 :
The final image in an astronomical telescope is _______ the original object . Fill in the gap.<br/>
Question 131 :
The reflecting surface is given by $y = \dfrac{10L}{\pi} \sin \dfrac{\pi x}{5L}$. The co-ordinates of the point where a horizontal ray becomes vertical after reflection is:
Question 132 :
Two thin lenses of power $+3.5D, -2D$ are placed in contact. Find the power of lens combination.
Question 133 :
A symmetric double convex lens is cut in two equal parts by a plane containing the principal axis. If the power of the original lens was 4 D, the power of a divided lens will be
Question 134 :
Let the x-z plane be the boundary between two transparent media. Medium $1$ in $z\ge 0$ has a refractive index of $\sqrt { 2 } $ and medium $2$ with $z< 0$ has refractive index of $\sqrt { 3 } $. A ray of light in medium $1$ given by the vector $\vec { A } =6\sqrt { 3 } \hat { i } +8\sqrt { 3 } \hat { j } -10\hat { k } $ is incident on the plane of separation. The angle of refraction in medium $2$ is:
