Question 1 :
State whether true or falseA convex mirror is used for obtaining a real and magnified image.
Question 2 :
Assertion: Magnetic field lines are continuous and closed.
Reason: Magnification of a convex mirror is always positive, but that of a concave mirror may be both positive or negative.
Question 3 :
Concave lens is used in cameras to focus an image of film. Is the statement True or False?<br/>
Question 4 :
The ratio of the sine of angle  of incidence to the sine of angle of refraction is a constant for :
Question 5 :
What is the formula for spherical mirrors for object distance p and image distance q ?<br/>
Question 6 :
On the basis of their experiment, "To trace the path of a ray of light through a rectangular glass slab," students of a class arrived at which one of the following conclusions :
Question 7 :
Which of the following mirrors forms an image which is virtual and smaller in size?
Question 8 :
If the magnification of a body of size 1 m is 2, what is the size of the image?
Question 9 :
"Value of refractive index remains same for light rays with different wavelength and for a particular material"
Question 11 :
Due to refraction, when seen from outside,a coin placed under water in a bowl, appears to
Question 12 :
When the height of the image is less than the height of the object, then magnification will be
Question 13 :
A focal length of a lens is 10 cm. What is power of a lens in dioptre?
Question 14 :
The power of a lens is $+2.0D$. Find its focal length and state the kind of the lens.<br>
Question 16 :
The mirror used in automobiles to see the rear field of view is
Question 17 :
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 18 :
A man sees a smallstationary fish deep in a very clear lake and shoots it accurately. He will
Question 20 :
Fill in the blank. A _____ is a piece of transparent glass bounded by two spherical surfaces. 
Question 21 :
State whether the following statement is True or False. <br/>The image formed by a convex lens is real diminished and erect.
Question 22 :
When the object is at focus of a concave mirror, the image is formed at
Question 23 :
If the focal length of a lens is $50\;cm$, its power would be
Question 24 :
When a ray of light passes through a rectangular glass slab, the angle of emergence
Question 25 :
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 26 :
The power of a lens whose focal length is one metre is ______ dioptre.
Question 27 :
The focal length of a combination of lenses formed with lenses having powers of $+2.50\ D$ and $-3.75\ D$ will be
Question 28 :
For an object at infinity, a concave mirror produces an image at its focus which is :
Question 29 :
If $f$ is the focal length of a lens, then the power of the lens is equal to
Question 32 :
A ray of light is incident normally on a plane glass slab. What will be the angle of refraction ?
Question 33 :
State whether true or false.<br/>The images formed by a convex mirror are always erect and enlarged.
Question 34 :
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 36 :
Find the power (with sign) of a concave lens of focal length $20cm$.<br/>
Question 37 :
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 38 :
A ray of light is incident perpendicularly on a glass slab. The angle of incidence is :
Question 39 :
Which of the following is not a characteristic of the image formed by Convex lens ?
Question 40 :
The ratio of the size of the image to the size of the object is known as
Question 41 :
What is the nature of image formed by Concave lens ?
Question 43 :
State whether given statement is True or False<br/>A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.<br/>
Question 44 :
Ray optics fail when the size of the obstacle is :
Question 45 :
A man is unable to see closer than 1 m clearly.The power of lenses of his spectacles should be to see nearby object.
Question 46 :
When the face is very close to the spoon the image formed by the outside bulged part?
Question 48 :
The relation among $u$, $v$ and $f$ for a mirror is:
Question 50 :
The incident ray, the _______ ray and the normal lie in the same plane during refraction.
Question 51 :
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 52 :
The image of an object is formed by a convex lens. When that object is placed beyond the focal length is -
Question 53 : Gita arranges some mirrors in group- $1$ and group- $2$ according to the magnification, type of image and size of image from the following data.<table class="wysiwyg-table"><tbody><tr><td>Sr. No.</td><td>Group-$1$</td><td>Group-$2$</td></tr><tr><td>$(1)$</td><td>$<1$ and negative</td><td>Real, inverted and small</td></tr><tr><td>$(2)$</td><td>$>1$ and positive</td><td>Real, inverted and enlarged</td></tr><tr><td>$(3)$</td><td>$>1$ and negative</td><td>Virtual, erect and enlarged</td></tr><tr><td>$(4)$</td><td>$<1$ and positive</td><td>Virtual, erect and small</td></tr></tbody></table>For which of the pairs from the group $1$ and $2$ you disagree.
Question 54 :
A $4.0$-cm-high object is placed at a distance of $60$ cm from a concave lens of focal length $20$ cm. Find the size of the image.
Question 55 :
A virtual image larger than the object can be produced by a :
Question 56 :
If a lens has power -2.5D, then it is a :
Question 57 :
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 </b>from its second principal focus. Then the focal length of the lens is :
Question 58 :
The apparent flattening of the sun at sunset and sunrise is due to
Question 60 :
Magnification produced by spherical lens is $+2.5$. What is the nature of image?
Question 61 :
Power of a lens is -40 , its focal length is
Question 62 :
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 63 :
Two lenses one of focal length $20 cm$. (convex lens) and another of focal length $-15 cm$ (concave lens) are placed in contact. Identify the correct statement.
Question 64 :
The magnifications produced by a convex lens for two different of an object are $m_1$ and $m_2$ respectively $(m_1 >m_2)$. If 'd' is the distance of separation between the two positions of the object then the focal length of the lens is
Question 65 :
The focal length of a convex lens is $25cm$. Its power will be:
Question 66 :
In case of refraction of light<br/>a) Frequency changes <br/>b) Speed changes <br/>c) Wavelength changes<br/>
Question 67 :
In optical instruments, the lenses are used to form image by the phenomenon of
Question 68 :
A vertical ray of light strikes the horizontal surfaceof water.What is the angle of refraction?
Question 69 :
The angle between reflected and refracted beams is $90^0$in the water air interface. The angle of incidence in water is
Question 71 :
Two lenses whose powers are $4D$ and $-2D$ are kept in contact. The power of the compound lens is:
Question 72 :
Two thin lenses, when in contact, produce a combination of power$+10D$. When they are $0.25m$ apart, the power reduces to $+6D$. The focal lengths of the lenses (in m) are
Question 73 :
A sound wave is travelling in a medium in which the velocity is $v$. It is incident in the second medium in which the velocity of the wave is $2v$. What should be the minimum angle of incidence in the first medium, so that the wave fails to cross the surface of separation of the two media?
Question 74 :
The lens of a simple magnifier has a focal length of 2.5 cm. Calculate the angular magnification produced when (a) the image is at least distance of distinct vision, and (b) infinity.
Question 75 :
A ray of light moving along the unit vector $\dfrac{1}{\sqrt5}(\hat { -i  } -2\hat { j } )$ undergoes refraction at an interface of two media, which is the x-z plane. The refractive index for y > 0 is 2 while for y < 0, it is $\sqrt{5}$/2. The unit vector along which the refracted ray moves is
Question 76 :
A diverging meniscus lens has a focal length of -20 cm. If the lens is held 10 cm from the object, the magnification is :
Question 77 :
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 78 :
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
Question 79 :
A concave mirror produces $10$ times enlarged image (real) of an object placed $1 cm$ in front of it. Where is the image located?
Question 80 :
The focal length of a plano-convex lens is equal to its radius of curvature. The value of the refractive index of its material is
Question 81 :
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 82 :
The flat face of a plano-convex lens of focal length $10$cm is silvered. A point source placed $30$cm in front of the curved surface will produce a.
Question 83 :
An air bubble in a glass with refractive index $1.5$ (near normalincidence) i.e. $5\ cm$ deep when viewed from one surface and $3\ cm$ deep when viewed from the opposite face. The thickness(in $cm$) of the is.
Question 84 :
If two $+5D$ lenses are mounted at some distance apart, the equivalent power will always be negative if the distance is
Question 85 :
An object is placed at a distance $2 f$ from the pole of a convex mirror of focal length $f$ . The linear magnification is:<br/>
Question 86 :
A ray of light enters a medium of refractive index $\mu_m$. It is observed that the angle of refraction is half the angle of incidence. Then, the angle of incidence will be :
Question 87 :
A light of wavelength $6000A^{\circ}$ in air, enters a medium with refractive index $1.5$. Inside the medium its frequency is _________ $Hz$ and its wavelength is ______ $6000 A^{\circ}$.
Question 88 :
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
Question 89 :
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 91 :
A glass slab is placed in the path of convergent light. The point of convergence of light :
Question 92 :
The least distance of vision of a longsighted person is $60\ cm$. By using a spectacle lens, this distance is reduced to $12\ cm$. The power of the lens is
Question 93 :
Two thin lenses of focal lengths $20 cm$ and $25 cm$ are placed in contact. The effective power of the combination is
Question 94 :
A beam of light converges towards a point O, behind a convex mirror of focal length 20 cm. Find the magnification and nature of the image when point O is 30 cm behind the mirror.
Question 95 :
The image of an object placed in front of a concave mirror of focal length 12 cm is formed at a point which is 10 cm more distant from the mirror than the object. The magnification of the image is:<br/>
Question 96 :
A concave mirror forms the real image of an object which is magnified 4 times. The objects is moved 3 cm away, the magnification of the image is 3 times. What is the focal length of the mirror?
Question 97 :
An astronomical telescope has focal lengths $100$ & $10$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 99 :
An object is placed at a distance of $f/2$ from a convex lens. The image will be
Question 100 :
When light passes from air to glass, it experiences a change of:
Question 101 :
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:
Question 102 : 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 103 :
The angle between the incident ray and the normal is called ________.<br>
Question 104 :
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 105 :
Two thin lenses of power $+3.5D, -2D$ are placed in contact. Find the power of lens combination.
Question 106 :
A ray of light going towards the centre of curvature of a convex mirror ............
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 :
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 109 :
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 110 :
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 111 :
The diameter of the reflecting surface of spherical mirror is called ..............
Question 112 :
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 113 :
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 114 :
The image obtained while finding the focal length of convex lens is...................
Question 115 :
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 116 :
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 117 :
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 119 :
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 120 :
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 121 :
The glancing angle of incidence is $10^{\circ}$. What will be the glancing angle of reflection?
Question 122 :
The distance between an object and its doubly magnified image by a concave mirror is: [ Assume $f$ = focal length]
Question 123 :
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 124 :
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 125 :
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 126 :
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 127 :
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 128 :
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 129 :
The final image in an astronomical telescope is _______ the original object . Fill in the gap.<br/>
Question 130 :
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 131 :
What happens when a ray of light is made to fall on a mirror along the normal?<br/>
Question 132 :
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 133 :
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 134 :
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 136 :
The angle between the two refracting surface of a prism is called angle of :<br/>
Question 137 :
As the thickness of the atmosphere increases colour of scattered light is found in ________order.
Question 140 :
In context of scatteringFine particles : ____ wavelength : : large particles : _____ wavelength
Question 141 :
The phenomenon of scattering of light by fine particles is called _____ :<br/>
Question 145 :
What are the colours of the Sun observed most during sunrise/sunset and noon? <br/>
Question 146 :
The path of a beam of light is invisible in which solution?
Question 149 :
The rising and setting of sun appear red because of : 
Question 151 :
The rising and setting of sun appear red because of : 
Question 154 :
In context of scatteringFine particles : ____ wavelength : : large particles : _____ wavelength
Question 156 :
Why are red coloured lights are used in traffic signals to stop the vehicles?
Question 157 :
A disease, in which eye lens become cloudy and the opaque lens is removed and a new artificial lens is inserted, is :
Question 159 :
When white light enters a prism, its gets splits into its constituent colours. This is because of:<br/>
Question 161 :
During dispersion through prism, red light travels fastest and violet travels slowest of all the seven colours. As a result:
Question 162 :
The color of scattered light depends on ____ of the scattering particles.
Question 164 :
A person while reading a newspaper keeps it at a distance of $40$ cm, then he suffers from which of the following defects?
Question 165 :
Why do high rise buildings have a red light on the top of the building?
Question 166 :
The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light:<br/>
Question 169 :
Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?<br/>
Question 170 :
At which place in eye,image is formed of a person is far-sightedness (hypermetropia) ?
Question 171 :
In the white light of sun, maximum scattering by the air molecules present in the earth's atmosphere is for:<br>
Question 172 :
Fill in the blank spaces by choosing the correct word.A prism is a piece of transparent material having three rectangular surfaces and .......... triangular surfaces.
Question 175 :
A person cannot see fundamental colours (red, blue, green). This defect is called:
Question 177 :
Some stars appear red in colour and some blue in colour. Which one of the statements is true?<br>
Question 178 :
The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light:<br/>
Question 180 :
Why do high rise buildings have a red light on the top of the building?
Question 181 :
If the image of distant objects is formed in front of the retina, the defect of vision may be
Question 182 :
Why astronauts see dark sky in space unlike blue sky on earth:
Question 183 :
Some stars appear red in colour and some blue in colour. Which one of the statements is true?<br>
Question 184 :
In the white light of sun, maximum scattering by the air molecules present in the earth's atmosphere is for:<br>
Question 185 :
Which of the following phenomena cannot be explained by scattering of light ?
Question 187 :
Assertion: By roughening the surface of a glass sheet its transparency can be reduced. <br>Reason: Glass sheet with rough surface absorbs more light.
Question 189 :
In a beaker containing colloidal solution of sodium thiosulphate and a drop of con. sulphuric acid, light observed from side of beaker is:
Question 190 :
Assertion: Fine particles in atmosphere scatter the light of shorter wavelength more.
Reason: Sky appears blue.
Question 191 :
Assertion: A piece of red glass is heated till it glows in dark. The colour of glowing glass would be orange.
Reason: Red and orange is complementary colours.
Question 193 :
At sun rise or at sun set the sun appears to be reddish while at mid day it looks white. This is because
Question 194 :
Larger particles scatter light at the ____ end of the spectrum the least. <br/>
Question 198 :
At sunrise or sunset, the sun appears to be reddish white. This is because :
Question 199 :
Assertion: A Diamond sparkles more than a glass imitation cut to the same shape.
Reason: The refractive index of diamond is less than that of glass.
Question 200 :
Assertion: The setting sun appears to be red.
Reason: Scattering of light is directly proportional to the wavelength.
Question 202 :
During scattering of light, the amount of scattering is inversely proportional to ________ of wavelength of light.
Question 204 :
Assertion: The setting sun appears to be red. <br>Reason: Scattering of light is directly proportional to the wavelength.
Question 205 :
When is the direction of scattered light independent of the wavelength?
Question 206 :
Assertion: In the absence of atmosphere the sky would appear black.<br/>
Reason: Atmosphere scatters the light and hence we get blue colour.
Question 208 :
At sunrise or sunset, the sun appears to be reddish white. This is because :
Question 212 :
Assertion: The setting sun appears to be red.
Reason: Scattering of light is directly proportional to the wavelength.
Question 213 :
Assertion: By roughening the surface of a glass sheet its transparency can be reduced. <br>Reason: Glass sheet with rough surface absorbs more light.
Question 214 :
Which of the following phenomena cannot be explained by scattering of light ?
Question 217 :
Assertion: Incoming light reflected by earth is partially polarized.
Reason: Atmospheric particle polarize the light.
Question 218 :
Assertion: Bluish colour predominates in a clear sky, since blue has a shorter wavelength and is scattered strongly.
Reason: Blue has the shortest wavelength among all colours.
Question 219 :
Assertion: Incoming light reflected by earth is partially polarized.
Reason: Atmospheric particle polarize the light.
Question 222 :
Assertion: Bluish colour predominates in a clear sky, since blue has a shorter wavelength and is scattered strongly.
Reason: Blue has the shortest wavelength among all colours.
Question 226 :
What characteristic property of light is responsible for the blue colour of the sky?<br>
Question 229 :
Assertion: Fine particles in atmosphere scatter the light of shorter wavelength more.
Reason: Sky appears blue.
Question 230 :
During scattering of light, the amount of scattering is inversely proportional to ________ of wavelength of light.
Question 233 :
Assertion: A Diamond sparkles more than a glass imitation cut to the same shape.
Reason: The refractive index of diamond is less than that of glass.
Question 234 :
In a beaker containing colloidal solution of sodium thiosulphate and a drop of con. sulphuric acid, light observed from side of beaker is:
Question 235 :
The process of re-emission of absorbed light in all directions with different intensities by the atom or molecule is called ____________.
Question 236 :
A person is wearing spectacles with concave lenses for correcting vision. While not using the glasses, the image of a distant object in his case will be formed<br>
Question 238 :
Myopia or near sightedness is a defect of eyes in which<br>
Question 239 :
A normal eye is not able to see objects closer than $25$cm because?
Question 240 :
The angular magnification of telescope is $30$. If all the light which passes through objective lens of diameter $80 cm$ also passes through eye piece lens then find out diameter of eye piece lens.
Question 241 :
The defective condition of accommodation of the eye in which distant objects are clearly seen but near objects are indistinct is<br>
Question 244 :
In old age farsightedness is a defect of eye in man, in which
Question 246 :
The process of re-emission of absorbed light in all directions with different intensities by the atom or molecule is called ____________.
Question 247 :
When the light rays converge at a point in front of the retina and then divert to form a blurred image on it, the defect is known as<br>
Question 249 :
Two point white dots are 1 mm apart on a black paper. They are viewed by eye of diameter $3\ mm $.<br/>Approximately, what is the maximum distance at which these dots can be resolved by the eye?<br/>[ take wavelength of light >500nm]
Question 250 :
One of the following is not an example of incomplete sex-linkage
