Light reflection and refraction Worksheet-26

Light reflection and refraction Worksheet-26

41. The refractive index of diamond is

A. 1.5                   B. 1.33                C. 2.42               D. 1.8

42. Light travels fastest in

A. vacuum         B. air                   C. glass               D. diamond

43. When a ray of light travels from water to glass, it bends

A. towards normal

B. away from normal

C. neither towards nor away from normal

D. cannot say

44. No refraction occurs when ray goes from

A. rarer to denser medium

B. denser to rarer medium

C. one medium to other medium of same optical density

D. Cannot be said

45. Refractive index of glass w.r.t. air is 3/2. What is the refractive index of air w.r.t glass

A. 2/3                 B. 1                      C. Zero               D. 3/2

46. The apparent depth of a tank of water is 3 m. What is its actual depth?  [Take ^an_w = 4/3]

A. 4 m                 B. 7 m                 C. 8 m                D. 5 m

47. Focal length of a lens depends on

A. object distance                         B. nature of material

C. image distance                         D. none of these

48. Power of a convex lens of focal length 50 cm is

A. –2 D              B.                C. 2 D                 D.

49. To form an image twice the size of the object, using a convex lens of focal length 20 cm, the object distance must be

A. < 20 cm

B. > 20 cm

C. >20 cm and between 20 cm and 40 cm

D. Data given is insufficient

50. An object is placed at the centre of curvature of a concave mirror of focal length f. The distance between its image and pole is:

A. Equal to f                                   B. Between f and 2f

C. Equal to 2f                                D. Greater than 2f

Answer Key:

41. C
42. A
43. A
44. C
45. A
46. A
47. B
48. C
49. C
50. C