Question 1 : Suppose the vitreous humour of the eye dries off. Then what will be its effect on our eyes?

Question 2 : Some stars appear red in colour and some blue in colour. Which one of the statements is true?<br>

Question 3 : At sun rise of sunset, the sun looks more red than at mid-day because

Question 5 : The least distance of distinct vision for a defective eye is $75$ cm. What should be the focal length of the lens which will be used to read a book clearly at $25$ cm?

Question 6 : For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index lies between:

Question 9 : For the myopic eye, the far point is farther away than the normal.

Question 15 : By which optical phenomena the splitting of white light into seven constituent colours occur?<br>

Question 17 : The rising and setting of sun appear red because of :&#160;

Question 18 : A prism is a piece of transparent material having _____ triangular and _____ rectangular surfaces.

Question 19 : Why astronauts see dark sky in space unlike blue sky on earth:

Question 21 : What is the time difference between actual sunset and apparent sunset?

Question 24 : Why are red coloured lights are used in traffic signals to stop the vehicles?

Question 27 : In context of scatteringFine particles : ____ wavelength : : large particles : _____ wavelength

Question 28 : Which of the following lens is used to minimise myopia ?

Question 30 : Why do high rise buildings have a red light on the top of the building?

Question 35 : The danger signals installed at the top of tall buildings are red in&#160;colour. These can be easily seen from a distance because among all other colours, the red light:<br/>

Question 36 : The&#160;band of colours obtained on a screen on passing white light through a prism is&#160;called :

Question 38 : The inability among the elderly to see nearby objects clearly because of the weaking of the ciliary muscles is called

Question 39 : In context of scatteringFine particles : ____ wavelength : : large particles : _____ wavelength

Question 40 : The bluish colour of water in deep sea is due to:<br/>

Question 42 : A&#160;defect of vision caused due to excessive curvature of the cornea is:

Question 43 : Fine beam of light entering through a small hole in a dark room illuminates the particles in its path. Identify the effect associated with this process.<br/>

Question 46 : In the white light of sun, maximum scattering by the air molecules present in the earth's atmosphere is for:<br>

Question 47 : Why do high rise buildings have a red light on the top of the building?

Question 48 : Which colour of light is scattered the most(maximum) in the atmosphere?

Question 49 : Which of the following lens is used to minimise hypermetropia ?

Question 51 : Ratio of the size of the image to the size of the object is known as:

Question 52 : In passing through a boundary, refraction will not take place if

Question 53 : The heat of sun focussed by a convex lens on a piece of paper is capable of

Question 54 : State whether true or false :&#160;A concave lens will always give a virtual, erect and diminished image.

Question 55 : A concave lens forms the image of an object which is :<br><br>

Question 56 : Choose the correct answer:<br>The nature of image formed by convex mirror is:

Question 57 : Magnification is 0.5 when the object distance is 10 cm. Find the power of the concave lens :

Question 59 : What is the power of the lens, if the far point of a short sighted eye is $200\ cm$?

Question 61 : Under which of the following conditions will a convex mirror of focal length <i>f</i> produces an image ofreal object that is erect, diminished and virtual

Question 63 : Due to refraction, when seen from outside,a coin placed under water in a bowl, appears to

Question 64 : State whether true or false.<br/>A concave mirror always forms erect and diminished images.

Question 65 : What is the nature of image formed by Concave lens ?

Question 66 : What is the size of image when position of object is at F, position of image is at infinity and image formed through concave mirror?<br>

Question 67 : Which of the following is not an application of convex lens?

Question 68 : The focal length of a convex mirror is $20\ cm$ its radius of curvature will be

Question 69 : The focal length of convex lens is 30 cm and the size of image is quarter of the object, then the object distance is:-

Question 70 : The image formed in case of a convex mirror is always ________ .

Question 71 : When a ray of light passes through a rectangular slab, made up of some transparent material other than glass, the emergent ray is

Question 72 : When the face is very close to the spoon the image formed by the outside bulged part?

Question 73 : The power of a lens having a focal length of $1 cm$ is :<br/>

Question 74 : 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&#160; made by the light ray with the normal in each, greatest first.

Question 75 : Light moves from air into water. The light makes an angle of $47^{\circ}$ with the normal in the air. What angle will it make with the normal in the water?<br>The index of refraction for air is $1.00$.<br>The index of refraction for water is $1.33$

Question 76 : Find the focal length of a convex lens, if its power is +2.0 D.

Question 78 : A ray of light passes through a glass slab. and the angle of emergence is found smaller than the angle of incidence. So, we may conclude that the glass slab

Question 79 : The focal length of a convex lens is $25cm$. Find its power with sign.<br/>

Question 80 : Light moves from air into water. The light makes an angle of $47^0$ with the normal in the air. What angle will it make with the normal in the water?<br/>The index of refraction for air is $1.00$.<br/>The index of refraction for water is $1.33$.

Question 81 : The power of a lens having a focal length of $1\;cm$ is :

Question 83 : In case of a real and inverted image, the magnification created by the mirror is<br/>

Question 84 : The mirror which always produces an erect and virtual image of a real object is:<br/>

Question 85 : The ratio of the size of the image to the size of the object is known as

Question 87 : A plane glass plate is placed over a various coloured letters (violet, green, yellow, red). The letter which appears to raised more

Question 88 : A ray of light strikes the glass slab at an angle of $50^o$. Then the angle of incidence will be _____.

Question 89 : In case of a virtual and erect image, the magnification created by the mirror is

Question 90 : A wave has velocity v in medium P and velocity 2v in medium Q. If the wave is incident in medium P at an angle of 30, then the angle of refraction will be

Question 91 : Choose the correct statement(s) related to the motion of object and its image in the case of&#160; mirrors.

Question 92 : Height of the image of an object on an principal axis produced by a convex lens is double the focal length of lens is $20 cm$, then image distance from the lens is:

Question 93 : What is the power of a concave lens of focal length50 cm?

Question 94 : Lens A produces a magnification of -0.8 whereas lens B produces a magnification of +0.8. Which one of the following applies to lenses A and B?

Question 95 : A focal length of a lens is 10 cm. What is power of a lens in dioptre?

Question 96 : What is the formula for spherical mirrors for object distance p and image distance q ?<br/>

Question 97 : $ \dfrac{\sin i}{\sin r} &#160;=$constant, the value of constant depends&#160;upon<br/>a) Pair of media <br/>b) Color of incident light<br/>c) Wave length <br/>d) Refracting nature of material<br/>

Question 100 : State whether true or false.<br/>The images formed by a convex mirror are always erect and enlarged.

Question 101 : The image of an object formed by a convex lens when the object is placed between the lens and the focal point is -

Question 102 : An object is placed at a distance of $f/2$ from a convex lens. The image will be

Question 104 : An object is at 0.08 m from a magnifying lens and&#160;the image is formed 40 cm from the lens. The magnification produced is&#160;

Question 105 : The image of an object placed in front of a concave&#160;mirror of focal length 12 cm is formed at a point&#160;which is 10 cm more distant from the mirror than the object. The magnification of the image is:<br/>

Question 106 : Assertion: Power of the lens is larger if its focal length is smaller. Reason: Power of the lens measures the ability to converge or diverge the refracted rays.

Question 107 : 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 108 : 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 109 : The sun subtends an angle of $(1/2)^o$ at earth.The image of the sun is obtained on a screen using a converging lens of focal length 1.5 cm.The diameter of the image will be :

Question 110 : The magnification produced by a mirror is $+\dfrac{1}{3}.$ Then the mirror is a ____________.

Question 111 : If linear magnification for a spherical mirror is $\dfrac{3}{2}$, then we may write:&#160;(symbols have their usual&#160;meanings)&#160;

Question 112 : A ray of light falls into a medium of $R.l.\mu$ from vacuum. The angle of incidence is found to be twice the angle of refraction. Then, the angle of incidence is

Question 113 : 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 114 : 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 115 : You are given water, mustard oil, glycerine and kerosene. In whichof these media a ray of light incident obliquely at same angle wouldbend the most ?<br>

Question 116 : An object placed at a distance of <b>16 cm</b> from first principal focus of convex lens, produces a real image at a distance of <b>36 cm&#160;</b>from its second principal focus. Then the focal length of the lens is :

Question 118 : A thin layer of water is transparent but a very thick layer of water is

Question 119 : A ray of light is incident at an angle i on a glass slab of refractive index $\mu$. The angle between reflected and refracted light is $90^o$. Then the relationship between i and $\mu$ is.<br>

Question 120 : Height of the image of an principal axis produced by a convex lens is double the object height . If the focal length of the lens is $20 cm$, then the image distance from lens is :

Question 121 : An object is placed at a distance $2 f$ from the&#160;pole of a convex mirror of focal length $f$ . The&#160;linear magnification is:<br/>

Question 122 : Power of a lens is -40 , its focal length is

Question 123 : A ray of light travelling inside a rectangular glass block of refractive index $\sqrt2$ is incident on the glass-air surface at an angle o incidence of $45^o$.The refractive index of air is one. Under these conditions the ray will

Question 124 : A beam of red light ($7000$ A.U. in air) in passing from air into a medium making an angle of incidence of $61^o$ and angle of refraction of $34^o$. find the wavelength of red light in the medium.

Question 125 : The image of an object placed on the principal axis of a concave mirror of focal length $12\ cm$ is formed at a point which is $10\ c$ more distance from the mirror than the object. The magnification of the image is

Question 126 : Assertion: A ray of white lights shows no dispersion on emerging from a glass slab although occurs dispersion inside the glass slab. Reason: The velocity of light inside the glass slab is same for all different colours.

Question 127 : Assertion: Air bubble shines in water. Reason: Air bubble in water shines due to refraction of light.

Question 128 : A person cannot see objects clearly beyond $2.0\ m$. The power of lens required to correct his vision will be

Question 129 : Refractive indices of water and glass are 4/3 and 3/2 respectively. A ray of light travelling in water is incident on the water-glass interface at $30^0$. Calculate the sine of angle of refraction.

Question 131 : A virtual image larger than the object can be produced by a :

Question 132 : A double concave thin lens made out of glass ($\mu = 1.5 $) have radii of curvature 500 cm. This lens is used to rectify the defect in vision of a person. The far point of the person will be at

Question 133 : If a lens has power -2.5D, then it is a :

Question 134 : Let the $\mathrm{x}-\mathrm{y}$ plane be the boundary between two transparent media. Medium 1 in $\mathrm{z}\geq 0$ has a refractive index of $\sqrt{2}$ and medium 2 with $\mathrm{z}&lt; 0$ has a refractive index of $\sqrt{3}$. A ray of light in medium 1 given by the vector $\vec{\mathrm{A}}=6\sqrt{3}\hat{\mathrm{i}}+8\sqrt{3}\hat{\mathrm{j}} + 10\hat{\mathrm{k}}$ is incident on the plane of separation. The angle of refraction in medium 2 is<br>

Question 135 : When an object is moved along the principal axis of a thin converging lens of focal length 12 cm, two&#160;images, three times the size of the object are obtained when the object is at $x_1$ and $x_2$ distance from the lens. Which one of the following could be the value of the ratio $\frac {x_1}{x_2}$ ?

Question 136 : When an object is placed on the principal axis of a convex lens at two different positions, it produces the images with magnification +2 and -4 respectively. How many times more away from the lens the image will be formed in the second position as compared to the first position?<br>

Question 138 : An object 20 cm from a concave mirror form an image, double the size of the object, on a screen. How far should the screen be placed from the mirror?&#160;

Question 139 : The distance between an object and the screen is $100$cm. A lens produces an image on the screen when placed at either of two positions $40$cm apart. The power of the lens is approximately.

Question 140 : Where sunlight is concentrated on a piece of paper it starts burning. For doing this, the paper must be placed at the focus of :<br/>

Question 142 : State whether true or false :A concave lens is used as a magnifying glass

Question 143 : The image of an object is formed by a convex lens. When that object is placed beyond the focal length is -

Question 144 : An astronomical telescope has focal lengths $100$ &amp; $10$cm of objective and eyepiece lens respectively when final image is formed at least distance of distinct vision,magnification power of telescope will be,

Question 145 : The power of a lens is a measure of its degree of

Question 146 : White light is incident normally on a glass slab. Inside the glass slab,

Question 147 : Two lenses have powers +D and -2D respectively. The power of combination is:

Question 148 : Assertion: Farther the image greater is the magnification. Reason: Magnification is equal to the ratio of the distance of the object and that of the image.

Question 149 : A thin plane membrane separates hydrogen at27$^o$C from hydrogen at 127$^o$C, both being at thesame pressure. A plane sound wave enters from the cooler to the hotter side. If the angle of incidenceon the membrane is 30$^o$C, then the angle ofrefraction is <br>

Question 150 : A ray of light moving along the unit vector $\dfrac{1}{\sqrt5}(\hat { -i&#160; } -2\hat { j } )$ undergoes refraction at an interface of two media, which is the x-z plane. The refractive index for y &gt; 0 is 2 while for y &lt; 0, it is $\sqrt{5}$/2. The unit vector along which the refracted ray moves is

Question 151 : 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 153 : The distance between an object and its doubly magnified image by a concave mirror is: [ Assume $f$ = focal length]

Question 154 : 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 155 : 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 156 : 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 157 : 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 158 : 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 159 : When a light of wavelength $4000$ $\displaystyle \overset { \circ &#160;}{ A }&#160;$ 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&#160;$\displaystyle \frac { 5 }{ 2 }&#160;$ and&#160;$\displaystyle \frac { 4 }{ 3 }&#160;$ respectively.

Question 160 : 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 161 : The final image in an astronomical telescope is _______ the original object&#160;. Fill in the gap.<br/>

Question 162 : The angle between the incident ray and the normal is called ________.<br>

Question 163 : 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 164 : 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 $20\&#160; cm$ is placed in between the convex lens and the image, at a distance $26\&#160; cm$ from the convex lens, size of the new image is:

Question 165 : 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 166 : The glancing angle of incidence is $10^{\circ}$. What will be the glancing angle of reflection?

Question 167 : A ray of light going towards the centre of curvature of a convex mirror ............

Question 168 : 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 169 : 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 170 : 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 171 : The image obtained while finding the focal length of convex lens is...................

Question 172 : Two thin lenses of power $+3.5D, -2D$ are placed in contact. Find the power of lens combination.

Question 173 : 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 174 : 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 175 : 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 176 : 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 177 : The diameter of the reflecting surface of spherical mirror is called ..............

Question 178 : 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 179 : In the table below, column I lists various mirrors &#160;and lenses and column II their uses, qualities or properties.<br/><table class="wysiwyg-table"><tbody><tr><td>column &#160;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&#160;</td><td>D.&#160;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 180 : 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 $z&lt; 0$ 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:

Question 181 : 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 182 : 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 183 : 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 184 : What happens when a ray of light is made to fall on a mirror along the normal?<br/>