9. Which of the following is NOT a defect of vision?
(a) Myopia
(b) Hypermetropia
(c) Presbyopia
(d) Tyndall effect
Answer: (d) Tyndall effect
10. The sun appears red during sunrise and sunset due to:
(a) Dispersion
(b) Scattering
(c) Refraction
(d) Reflection
Answer: (b) Scattering
11. The angle of deviation in a prism depends on:
(a) Angle of incidence
(b) Angle of prism
(c) Both (a) and (b)
(d) None of these
Answer: (c) Both (a) and (b)
12. Which lens is used to correct hypermetropia?
(a) Concave
(b) Convex
(c) Bifocal
(d) Cylindrical
Answer: (b) Convex
13. The sky appears dark to astronauts because:
(a) There is no atmosphere
(b) Light is absorbed
(c) No scattering occurs
(d) Both (a) and (c)
Answer: (d) Both (a) and (c)
14. The far point of a myopic person is 80 cm. The power of the corrective lens required is:
(a) -1.25 D
(b) +1.25 D
(c) -0.8 D
(d) +0.8 D
Answer: (a) -1.25 D
15. Which phenomenon explains the advance sunrise and delayed sunset?
(a) Dispersion
(b) Scattering
(c) Atmospheric refraction
(d) Reflection
Answer: (c) Atmospheric refraction
True/False
1. The retina is a light-sensitive screen in the eye. Answer: True
2. The ciliary muscles help in changing the curvature of the eye lens. Answer: True
3. A concave lens is used to correct hypermetropia. Answer: False
4. The near point of a normal eye is 25 m. Answer: False
5. Dispersion of light occurs due to different wavelengths bending at different angles.
Answer: True
6. The blue colour of the sky is due to the reflection of light. Answer: False
7. Stars twinkle due to atmospheric refraction. Answer: True
8. Planets twinkle like stars. Answer: False
9. Presbyopia is caused by the elongation of the eyeball. Answer: False
10. The Tyndall effect is observed in true solutions. Answer: False
11. A prism can recombine the spectrum of white light. Answer: True
12. The danger signal is red because it is least scattered. Answer: True
13. The focal length of the eye lens decreases when viewing nearby objects.
Answer: True
14. The far point of a hypermetropic eye is less than infinity. Answer: False
15. A rainbow is formed in the direction of the sun. Answer: False
