Q.1
It is necessary to illuminate the bottom of well by reflected solar beam when the light is incident at an angle θ=40° to the vertical. At what angle to the horizontal should a plane mirror be placed to do this
  • a) 70°
  • b) 20°
  • c) 50°
  • d) 40°
Q.2
A virtual object placed between the pole and the principal focus of a convex mirror produce an real image which is
  • a)real, magnified and upright
  • b) virtual, diminished and inverted
  • c)virtual, diminished and upright
  • d)real, diminished and inverted
Q.3
It is desired to photograph the image of an object placed at a distance of 3m from a plane mirror. The camera, which is at a distance of 4.5m from the mirror should be focaused for a distance of
  • a) 3 m
  • b) 4.5 m
  • c)6 m
  • d)7.5 m
Q.4
How many images of himself does an observer see if two adjacent walls of rectangular room are mirror surfaced
  • a) 3
  • b) 5
  • c)7
  • d)9
Q.5
Sun subtends an angle of (1/2)° at the centre of curvature of 15m. The size of the image of the sun formed by the mirror is
  • a) 8.55 cm
  • b) 7.55 cm
  • c) 6.55 cm
  • d) 5.55 cm
Q.6
A concave mirror of focal length 200cm is used to obtain the image of the sun which subtends an angle of 30'. Then the diameter of the image of the solar disc is
  • a)3.48 cm
  • b) 1.74 cm
  • c)0.87 cm
  • d)200 cm
Q.7
A spherical mirror forms diminished virtual image of the magnification 1/Focal length is 18cm. the distance of the object is
  • a) 18 cm
  • b) 36 cm
  • c)48 cm
  • d)∞
Q.8
A cubical room is formed with six plane mirrors. An insect moves along the diagonal of the floor with uniform speed. The velocities of its image in two adjacent walls are 20√2 cm/sec, then the velocity of the image formed by the roof is
  • a) 20 cm/sec
  • b) 40 cm/sec
  • c)20√2 cm /sec
  • d)10√2 cm/sec
Q.9
The image formed by convex mirror of focal length 30cm is quarter of the size of the object. Then the distance of the object from the mirror is
  • a) 30 cm
  • b) 90 cm
  • c) 120 cm
  • d) 60 cm
Q.10
A convex mirror has a focal length f. A real object is placed at a distance f/2 in front of it from the pole. the mirror produces an image at
  • a)infinity
  • b) f
  • c)2f
  • d)f/3
Q.11
Which of the following can not produce a virtual image
  • a) Plane mirror
  • b) concave mirror
  • c)concave lens
  • d)all of them can produce a virtual image
Q.12
An object is placed at a distance of 25cm from the pole of convex mirror and plane mirror is set so that the virtual image is formed by the to mirror is 20 cm from the object. the focal length of the mirror is
  • a) 37.5 cm
  • b) -7.5 cm
  • c)-37.5 cm
  • d)+75 cm
Q.13
A convex and concave mirror of radii 10 cm each are facing each other and 15cm apart. A point object is placed mid-way between them. Then the position of the final image if the reflection first takes place at the concave mirror is
  • a) At the pole of concave mirror
  • b) At the pole of the convex mirror
  • c) coincident ith the convex mirror
  • d) none of these
Q.14
A spherical mirror forms a real image of a point object placed in front. The distance of the image and object from the mirror is 30cm and 0.2 m respectively. The focal length and nature of the mirror are
  • a)120 mm, concave
  • b) 120mm, convex
  • c)60 cm, concave
  • d)60 cm, convex
Q.15
A concave mirror of focal length f produces an image n times the size of the object. If the image is real, then the distance of the object from the mirror is
  • a) (n-1)f
  • b)(n-1)f / n
  • c)(n+1)f / n
  • d)(n+1)f
Q.16
A thin rod of length f/3 lies along the axis of a concave mirror of focal length f. One end of its image touches the end of the rod. The length of the image is
  • a) f
  • b) f/2
  • c)2f
  • d)f/4
Q.17
Thee image of the sun is formed by a concave mirror. the lower half of the mirror is now coated black. Which of the following statement is correct?
  • a) the image size is reduced to half
  • b) the size of the image and intensity remains same
  • c) the size of the image remains same but it is less intense
  • d) the size and intensity of the image is reduced to half
Q.18
The sun has a diameter of 864100 miles and is on an average at a distance of 92900000 miles from the earth. Concave mirror of radius 6 metres is used to obtain its image. the diameter of the image of the solar disc is
  • a)28 metres
  • b) 28 cm
  • c)28 mm
  • d)28×10⁻¹ mm
Q.19
Figure shows a cubical room ABCD with wall CD as a plane mirror. Each side of the room is 3m. We place a camera at the mid point of the wall AB. At what distance should the camera be focused to photograph an object placed at A
ch-11_que_no-214_img_no1.png
  • a) 1.5 cm
  • b) 3 m
  • c)6 m
  • d)more than 6 m
Q.20
A ray of light makes an angle of 10° with the horizontal and strikes a plane mirror which is inclined at an angle θ to the horizontal. The angle θ for the reflected ray becomes vertical, is
  • a) 40°
  • b) 80°
  • c)50°
  • d)100°
Q.21
A clock hung on a wall has marks instead of numerals in its dial. On the adjoining wall there is a plane mirror and the image of the clock in the mirror indicates the time 4.Then the time on the clock is
  • a) 7.40
  • b) 4.20
  • c) 2.40
  • d) 4.07
Q.22
For a convex mirror, the variation of u vs v is given by
  • a)
    ch-11_qn-217choice_img_no1.png
  • b)
    ch-11_qn-217choice_img_no2.png
  • c)
    ch-11_qn-217choice_img_no3.png
  • d)
    ch-11_qn-217choice_img_no4.png
Q.23
A aluminum object is placed 20 cm from the surface of a convex mirror and a plane mirror it set so that the virtual images formed in two mirrors coincides. If the plane mirror is at a distance of 12 cms from the object, then the focal length of the convex mirror is
  • a) 10 cm
  • b) 5 cm
  • c)20 cm
  • d)40 cm
Q.24
A man wearing yellow coloured glass for left eye and red coloured glass for right eye stand in front of a plane mirror. Which of the following statement is correct?
  • a) Both eyes are red colour
  • b) Both eyes are of yellow colour
  • c)Left eye is yellow coloured and right red
  • d)Left eye is red and right is yellow
Q.25
A point object O is placed between two plane mirrors as shown in figure. The distance of the first three images formed by mirror M2 form it are
ch-11_que_no-220_img_no1.png
  • a) 2 mm, 8 mm, 18 mm
  • b) 2 mm, 18 mm, 28 mm
  • c) 2 mm, 18 mm, 22 mm
  • d) 2 mm, 18 mm, 58 mm
Q.26
Two plane mirrors M1 and M2 have a length of 2m each and are 10 mm apart. A ray of light is incident on one end of the mirror M2 at an angle of 30°. The number of reflections light undergoes before reaching the other end is
ch-11_que_no-221_img_no1.png
  • a)170
  • b) 100
  • c)150
  • d)200
Q.27
A point object is placed at a distance of 500 mm from a concave mirror of focal length 200 mm. If the object is moved towards the mirror by 100 m, the image moves by a distance of
  • a) 67 mm towards mirror
  • b) 67 mm away from the mirror
  • c)10 mm towards mirror
  • d)10 mm away from the mirror
Q.28
A candle is placed in front of a concave mirror. The image of candle is formed on wall at a distance of 2m from the candle. The size of the image is 6 times that of the candle. The distance of the candle from the mirror is
  • a) 1.6 m
  • b) 2.4 m
  • c)2.0 m
  • d)0.4 m
Q.29
A object is placed at a distance of 2f from a concave mirror. Light reflected from the mirror falls on a plane mirror. The distance of the plane mirror from the concave mirror equals f. The distance of the final image from the concave mirror ( due to reflection at both concave and plane mirror ) is
  • a) f
  • b) f/2
  • c) 2f
  • d) zero
Q.30
A concave mirror forms an image one -fourth the size of the object. If object is at a distance of 0.5 m from the mirror, the focal length of mirror is
  • a)0.16 m
  • b) -1.5 m
  • c)0.4 m
  • d)-0.4 m
Q.31
A concave mirror of focal length f from an image of the same size as the object. The distance of the object from the mirror is
  • a) f
  • b) f/2
  • c)2f
  • d)4f
Q.32
A driver mirror consists of a cylindrical mirror of radius 5cm and the length over the curvered surface is 10cms. If the eye of the driver be assumed to be at a great distance from mirror, then field of view in radian is
  • a)0.5
  • b)1.0
  • c)2.0
  • d)Indeterminate
Q.33
A concave mirror of focal length 20cms produces an image twice the size of the object. If the image is real, then the distance of the object from the mirror is
  • a) 20 cm
  • b) 10 cm
  • c) 30 cm
  • d) 60 cm
Q.34
A concave mirror forms, on a screen a real image of twice the linear dimensions of the object. Object and screen are then moved until the image is three times the size of the object. If the shift of the screen is 25cm, then the focal length of the mirror is
  • a)5 cm
  • b) 16.60 cm
  • c)25 cm
  • d)37.5 cm
Q.35
An object infront of plane mirror is displaced by 0.8 m along a straight line at an angle 30° to the mirror plane. The change in the distance between the object and image is
  • a) 0.20 m
  • b) 0.40 m
  • c)0.68 m
  • d)0.8 m
Q.36
Light of λ=500nm is travelling in air. Thin glass plate (µ=1.5 ) of thickness 1 mm is placed in the path of light. The change in phase of light is
  • a) zero
  • b) π/2
  • c)π
  • d)3π/2
Q.37
A bird in air looks at fish vertically below it and inside water X is the height of the bird above the surface of water and Y the depth of the fish below the surface of water. If the refractive index of water with respect to air is µ, the distance of the fish as observed by the bird is
  • a) X + Y
  • b) X + (Y/µ)
  • c) µX + Y
  • d) µX + µY
Q.38
Light passes from air to liquid. The angle of incidence is 60°. The deviation produced is 15°. The refractive index of the liquid is
  • a)1.5
  • b) 1.33
  • c)1.22
  • d)1.63
Q.39
Light of wave length 7200Å in air has a wave length in glass ( µ=1.5) equal to
  • a) 7200 Å
  • b) 4800 Å
  • c)10800 Å
  • d)7201.5Å
Q.40
Successive wave fronts propagating in a material medium are shown in figure. The refractive index of the medium
ch-11_que_no-235_img_no1.png
  • a)increases as Y increases
  • b) increases as X- increases
  • c)decreases as Y decreases
  • d)Velocity of light and wave length of the wave decreases with
Q.41
The phenomenon of dispersion arises because of
  • a) the decomposition of white light beam by a prism
  • b) the refraction of light
  • c) The refractive index of the prism material
  • d) the corpuscular nature of matter
Q.42
Which of the following represents correctly the variation of angle of deviation (δ) with angle of incidence(i) for refraction at prism
  • a)
    ch-11_qn-237choice_img_no1.png
  • b)
    ch-11_qn-237choice_img_no2.png
  • c)
    ch-11_qn-237choice_img_no3.png
  • d)
    ch-11_qn-237choice_img_no4.png
Q.43
A lens formed a sharp image on a screen. On inserting a parallel side slab of glass between the lens and the screen it is found necessary to move the screen a distance d ways from the lens in order to form the sharp image. If the refractive index of the glass slab relative to air is µ, then the thickness of the slab is
  • a) d / µ
  • b) µ/d
  • c)µd / (µ - 1)
  • d)(µ-1)d/ µ
Q.44
A point source is located 275 cm below the surface of lake. The area of the surface that transmits all the light that emerges from the surface is
  • a) 3.04 m2
  • b) 304 m2
  • c)30.4 m2
  • d)30 m2
Q.45
Refractive index is
  • a) directly proportional to wave length of light
  • b) Inversely proportional to wave length of light
  • c) Inversely proportional to square of wavelength of light
  • d) Directly proportional to the square of wavelength of light
Q.46
Glass prism has refractive index 1.5 and the refracting angle is 90°. If a ray falls on it at angle of incidence of 30°, then the angle of emergence will be
  • a)60°
  • b) 30°
  • c)45°
  • d)the ray will not emerge out of this prism
Q.47
The face PR of a prism PQR of an angle 30° is silvered. A ray is incident on face PQ at an angle of 45° as shown in figure. The refracted ray undergoes reflection on face PR and retraces its path. The refractive index of the prism is
ch-11_que_no-242_img_no1.png
  • a) √2
  • b) 3/√2
  • c)1.5
  • d)1.33
Q.48
An equilateral prism is made of material of refractive index √The angle of minimum deviation for the prism is
  • a) 30°
  • b) 45°
  • c)60°
  • d)90°
Q.49
Two medium are separated by a plane surface. Speed of light in one medium is 2 ×1010 cm/sec and in the other, it is 2.4×1010 cm/sec. Deduce the critical angle for a ray going from the first medium into the second
  • a) sin⁻¹(1/2)
  • b) sin⁻¹(5/6)
  • c) sin⁻¹(5/12)
  • d) sin⁻¹(1/√2)
Q.50
A bucket contains transparent liquid and its depth is 40cm. On looking from above bottom appears to be raised up by 8cm. The refractive index of the liquid is
  • a)5/4
  • b) 5
  • c)4/5
  • d)8/5
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