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WorksheetsLight - Reflection and Refraction
Total questions: 25
Worksheet time: 19mins
A child walks towards a fixed plane mirror at a speed of 5 km h–1. The velocity of the image with respect to mirror is -
(A) 5 km h–1
(B) –5 km h–1
(C) 10 km h–1
(D) –10 km h–1
According to laws of reflection of light -
(A) Angle of incidence is equal to the angle of reflection
B) Angle of incidence is less than the angle of reflection
(C) Angle of incidence is greater than the angle of reflection
(D) None of these
A light ray falls on a mirror and deviates by 60° then the angle of reflection will be
(A) 30°
(B) 90°
(C) 60°
(D) 180
The path along which light travels in a homogeneous medium is called a-
(A) beam of light
(B) ray of light
(C) pencil of light
(D) none of these
The magnification produced by a concave mirror -
(A) is always more than one
(B) is always less than one
(C) is always equal to one
(D) may be less than or greater than one
The image formed by a concave mirror is real, inverted and of the same size as that of the object. The position of the object should be-
(A) Beyond C
(B) Between C and F
(C) At C
(D) At F
The magnification of an object placed 10 cm from a convex mirror of radius of curvature 20 cm will be-
(A) 0.2
(B) 0.5
( C) 1
(D) infinity
The image formed by a concave mirror is observed to be virtual, erect and larger than the object. then the position of the object should be-
(A) between the focus and the centre of curvature
(B) at the centre of curvature
(C) beyond the centre of curvature
(D) between the pole of the mirror and the focus
Refractive index of glass with respect to air is 1.5 and refractive index of water with respect to air is 4/3 . What will be the refractive index of glass with respect to water ?
(A) 1
(B) 1.5
(C) 1.125
(D) –10
A ray of light is incident normally on a rectangular piece of glass. The value of angle of refraction will be-
(A) 180°
(B) 90°
(C) 45°
(D) 0°
The power of a lens having focal length 50 cm is-
(A) 0.5D
(B) 2D
(C) 3D
(D) 0.2 D
A convex lens forms a real image of a point object placed on its principal axis. If the upper half of the lens is painted black.
(A) the image will be shifted backward
(B) the image will not be shifted
(C) the intensity of the image will decrease
(D) both (B) and (C)
The minimum distance between an object and its real image formed by a convex lens of focal length f is-
(A) f
(B) 2f
(C) 3f
(D) 4f
The rear view mirror of a car is a plane mirror. A driver is reversing his car at a speed of
2 m/s. The driver sees in his rear view mirror the image of truck parked behind his car. The speed at which the image of the truck appears to approach the driver will be-
(A) 1 m/s
(B) 2 m/s
(C) 4 m/s
(D) 8 m/s
David is observing his image in a plane mirror. The distance between the mirror and his image is 5m. If he moves 1m towards the mirror, then the distance between David and his image will be-
(A) 3 m
(B) 5 m
(C) 6 m
(D) 8 m
A clock hung on a wall has marks instead of numbers on its dial. On the opposite wall there is a mirror, and the image of the clock in the mirror if read , indicates the time as 8.20. What is the time in the clock –
(A) 3.40
(B) 4.40
(C) 5.20
(D) 4.20
The ratio of the refractive index of red light to blue light in air is
(A) Less than unity
(B) Equal to unity
(C) Greater than unity
(D) Less as well as grater than unity depending upon the experimental arrangement
Myopia can be removed by using a lenses of
(A) concave lens
(B) convex lens
(C) cylindrical lens
(D) by surgical removal
When a ray of light enters a glass slab from air –
(A) Its wavelength decreases.
(B) Its wavelength Increases.
(C) Its frequency increases
(D) Neither wavelength nor frequency changes.
Two objects A and B when placed in turn in front of a concave mirror of focal length 7.5 cm, give images of equal size. If A is three times the size of B and is placed 30 cm from mirror , what is the distance of B from the mirror –
(A) 10 cm
(B) 12.5 cm
(C) 15cm
(D) 17.5 cm
A lens of power +2.0D is placed in contact with another lens of power -1.0D, the combination will behave like :-
(A) A converging lens of focal length 100 cm
(B) A diverging lens of focal length 100 cm
(C) A converging lens of focal length 50 cm
(D) A diverging lens of focal length 50 cm
An object 5.0 cm in length is placed at a distance of 20 cm in front of a convex mirror or radius of curvature 30 cm. The position of the image is
(a) 8.57 cm
(b) 9.10 cm
(c) 8.15 cm
(d) 7.15 cm
Assertion : Convex mirror is used as a shaving mirror. Reason : Convex minor always forms an enlarged image.
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(c) Assertion is true but Reason is false.
(d) Both Assertion and Reason are false
Assertion : The twinkling of star is due to reflection of light. Reason : The velocity of light changes while going from one medium to the other.
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(c) Assertion is true but Reason is false.
(d) Both Assertion and Reason are false.
Assertion : A concave mirror of focal length ‘f’ in air is used in a medium of refractive index 2. Then the focal length of mirror in medium becomes double. Reason : The radius of curvature of a mirror is double of the focal length.
(a) Both Assertion and Reason are true and Reason is the correct explanation of Assertion.
(b) Both Assertion and Reason are true but Reason is not the correct explanation of Assertion.
(c) Assertion is true but Reason is false.
(d) Both Assertion and Reason are false
