Question 2 :
In order to get a diminished virtual image, the object can be placed anywhere in front of a :
Question 4 :
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 $25\ cm$)
Question 8 :
The image formed by the given convex mirror when it is inside focal distance is:
Question 10 :
The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object?
Question 12 :
Where should the object be placed in front of a concave mirror so that the image formed is of the same size as the object?
Question 14 :
The focal length of a combination of lenses formed with lenses having powers of $+2.50\ D$ and $-3.75\ D$ will be
Question 15 :
A short sighted person can see distinctly only those objects which lie between $10cm$ and $100cm$ from him, The power of the spectacle lens required to see a distance object is
Question 16 :
A unit vector along the incident ray of light is $\hat{i}$. The unit vector for the corresponding refracted ray of light is $\hat{r}\cdot \hat{n}$, a unit vector normal to the boundary of the medium and directed towards the incident medium. If $\mu$ is the refractive index of the medium, then Snell's law (second law) of refraction is :
Question 17 :
What is the power of a concave lens of focal length50 cm?
Question 19 :
According to laws of refraction, refraction of light at the boundary between two different regions follow:
Question 20 :
The value of the focal length of the lens is equal to the value of the image distance when the rays are
Question 21 :
The distance between an object and its real image produced by a converging lens is $0.72\ m$. The magnification is $2$. What will be the magnification when the object is moved by $0.04\ m$ towards the lens?
Question 22 :
"Value of refractive index remains same for light rays with different wavelength and for a particular material"
Question 23 :
If an object is placed at '$C$' of a concave mirror, the position of the image is ______
Question 27 :
A camera is an optical instrument which makes use of a :
Question 28 :
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 29 :
The focal length of a convex mirror is $20\ cm$ its radius of curvature will be
Question 30 :
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 31 :
When a monochromatic light wave passes from air to glass across a plane surface of separation then:
Question 32 :
State whether true or false:A concave lens forms a magnified or diminished image depending on the distance of object from it.<br/>
Question 33 :
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 34 :
A photograph of a horse is taken by a camera whose lens has been painted with black stripes. The photograph will be of a :
Question 36 :
A ray of light coming parallel to the principal axis after passing through a convex lens, has passed through its :
Question 37 :
Fill in the blank. A _____ is a piece of transparent glass bounded by two spherical surfaces. 
Question 38 :
Concave lens is used in cameras to focus an image of film. Is the statement True or False?<br/>
Question 40 :
If the power of a lens is $0.1\;D$, its focal length is
Question 41 :
Material $1$ has an index of refraction of $1.15$.<br/>Material $2$ has an index of refraction of $2.30$.<br/>If light passes from air into each of these materials at the same angle of incidence, how will the angle of refraction in material $1$ compare to the angle of refraction in material $2$?
Question 42 :
State whether true or false.<br/>The images formed by a convex mirror are always erect and enlarged.
Question 43 :
Which of the following are common to images formed by both Concave and Convex lens ?
Question 46 :
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 47 :
A ray of light travels from air to glass at an angle of incidence of $37^{\circ}$, the angle of refraction is $24^{\circ}$. What is the refractive index of glass?<br/>(Given: $\sin 37^{\circ} = 0.60, \sin 24^{\circ} = 0.40)$
Question 48 :
If a $3cm$ tall object placed perpendicular to principal axis of a convex lens of focal length $15cm$ produces a real invented image of height $15cm$, then its object distance $(u)$ is ................ and image distance $(v)$ is ................
Question 52 :
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 53 :
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 54 :
The expression for the magnification of a spherical mirror in the terms of focal length (f) and the distance of the object from mirror (u) is
Question 56 :
The image of an object is formed by a convex lens. When that object is placed beyond the focal length is -
Question 57 :
Magnification produced is +$\dfrac { 1 }{ 3 }$, then what kind of mirror it is?
Question 58 :
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 59 :
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 60 :
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 61 :
For which of the following is $f > 0$:<br/><br/>I. Concave mirror<br/>II. Convex mirror<br/>III. Converging lens<br/> 
Question 62 :
When a ray of light traveling from vacuum to a medium of refractive index $\mu $, the angle of incidence is twice the angle of refraction. The incident angle is :<br/>
Question 63 :
A slide projector gives a magnification $10.$ If a slide of dimensions $3$ cm $\times$ $2$ cm is projected on the screen the area of image screen is
Question 64 :
A person cannot see objects clearly beyond $2.0\ m$. The power of lens required to correct his vision will be
Question 65 :
A fish is looking at a $1.0m$ high plant of the edge of the pond. Will the plant appear shorter or taller than its actual height, to the fish
Question 66 :
Assertion: Air bubble shines in water.
Reason: Air bubble in water shines due to refraction of light.
Question 67 :
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 68 :
Light of wavelength$\displaystyle 6600\overset { \circ }{ A }$ travelling in air gets refracted in water. If the speed of light in air is$\displaystyle 3\times { 10 }^{ 8 }{ m }/{ s }$ and R.I of water is 4/3. Find frequency of light in air.
Question 69 :
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 70 :
An object is placed at a distance $2 f$ from the pole of a convex mirror of focal length $f$. The linear magnification is:
Question 71 :
In an optical instrument a convex lens of focal length 20 cm is used and kept in contact with a concave lens of focal length 40 cm, What is the power of this combination?
Question 72 :
A ray of light is travelling through a medium of refractive index $\dfrac {1}{\sqrt {2}}$ with respect to air. When it is incident on the surface making an angle $45^{\circ}$ with the surface, which of the following will take place?
Question 74 : After tracing the path of a ray of light passing through a rectangularglass slab for four different values of the angle of incidence, a studentreported his observations in tabular form as given below :<br><table class="wysiwyg-table"><tbody><tr><td><br>S.No</td><td><i</td><td><r</td><td>< e</td></tr><tr><td><br>I</td><td>${30^0}$</td><td>${19^0}$</td><td>${29^0}$<br></td></tr><tr><td>II</td><td>${40^0}$</td><td>${28^0}$</td><td>${40^0}$</td></tr><tr><td>III</td><td>${50^0}$</td><td>${36^0}$</td><td>${50^0}$</td></tr><tr><td>IV</td><td>${60^0}$</td><td>${40^0}$</td><td>${59^0}$</td></tr></tbody></table>The best observation is :
Question 75 :
Two thin lenses of focal length $f_1$ and $f_2$ are in contact and coaxial. The power of the combination is __________.
Question 76 :
Frosted glass is widely used for translucent windows. The region where a transparent adhesive tape is stuck over the frosted glass becomes transparent. The most reasonable explanation for this is :
Question 77 :
A person needs a lens of power -4.5 D for correction of her vision. What is the focal length of the corrective lens?<br/>
Question 78 :
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 79 :
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 83 :
In aerial mapping a camera uses a lens with a $100\ cm$ focal length. The height at which the airplane must fly,so that the photograph of a $1\ km$ long strip on theground fits exactly on the $20\ cm$ long filmstrip of thecamera, is
Question 84 :
State whether true or false :A transparent material bound by two surfaces, of which one or both surfaces are spherical, forms a lens.
Question 85 : 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 86 :
Sometimes blurred and less sharply defined images are formed. This defect is called
Question 87 :
An object is placed at 20 cm in front of a concave mirror produces three times magnified real image. What is focal length of the concave mirror?
Question 88 :
A convex lens has focal length $30$cm. If an object is placed at a distance of $15$cm from it then the magnification produced by the lens is?
Question 89 :
If an object is placed at a distance of 20cm from the pole of a concave mirror, the magnification of its real image is 3. If the object is moved away from the mirror by 10cm, then the magnification is -1.
Question 90 :
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 91 :
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 92 :
A ray of light travels from ethanol into air. If the angle of incidence of the ray at the boundary is $30^0$ and the refractive index of ethanol is 1.36, what is the angle of refraction of the ray as it emerges out of ethanol?
Question 93 :
A lens of focal lengths $20 cm$ produces a real image of a stationary object having magnification $2$. Find the distance by which the lens should be moved so that it produces a virtual image of the same magnification.<br/>
Question 94 :
When light passes from air to glass, it experiences a change of:
Question 95 :
In passing through a boundary, refraction will not take place if:
Question 96 :
Two convex lenses of focal lengths $f_{1}$ and $f_{2}$ form images with magnification $m_{1}$ and $m_{2}$, when used individually for an object kept at the same distance from the lenses. Then $f_{1}/f_{2}$ is:
Question 97 :
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 98 :
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 99 :
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 100 :
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 101 :
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 102 :
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 103 :
The image obtained while finding the focal length of convex lens is...................
Question 104 :
Two thin lenses of power $+3.5D, -2D$ are placed in contact. Find the power of lens combination.
Question 105 :
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 106 :
The glancing angle of incidence is $10^{\circ}$. What will be the glancing angle of reflection?
Question 107 :
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 108 :
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 109 :
What happens when a ray of light is made to fall on a mirror along the normal?<br/>
Question 110 :
The final image in an astronomical telescope is _______ the original object . Fill in the gap.<br/>
Question 111 :
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 112 :
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 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 :
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 115 :
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 116 :
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 117 :
The diameter of the reflecting surface of spherical mirror is called ..............
Question 118 :
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 119 :
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 120 :
A ray of light going towards the centre of curvature of a convex mirror ............
Question 121 :
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 122 : 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 123 :
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 124 :
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 125 :
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 126 :
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 128 :
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 129 :
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 130 :
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 131 :
The angle between the incident ray and the normal is called ________.<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 :
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 134 :
The distance between an object and its doubly magnified image by a concave mirror is: [ Assume $f$ = focal length]
