SECTION A: QUESTIONS
Q1. Light travels in _______ lines.
(A) curved
(B) straight
(C) zigzag
(D) circular
Q2. The bouncing back of light is called:
(A) refraction
(B) reflection
(C) dispersion
(D) scattering
Q3. According to laws of reflection, angle of incidence is _______ angle of reflection.
(A) greater than
(B) less than
(C) equal to
(D) twice
Q4. A concave mirror is also called:
(A) diverging mirror
(B) converging mirror
(C) plane mirror
(D) flat mirror
Q5. The center of a spherical mirror is called:
(A) focus
(B) center of curvature
(C) pole
(D) aperture
Q6. Focal length is _______ of radius of curvature.
(A) double
(B) half
(C) equal
(D) one-fourth
Q7. The bending of light when it passes from one medium to another is called:
(A) reflection
(B) refraction
(C) dispersion
(D) absorption
Q8. A convex lens is _______ at the center.
(A) thinner
(B) thicker
(C) equal
(D) hollow
Q9. The SI unit of power of lens is:
(A) meter
(B) centimeter
(C) dioptre
(D) watt
Q10. The colored part of the eye is:
(A) cornea
(B) iris
(C) pupil
(D) retina
Q11. The minimum distance of distinct vision is:
(A) 15 cm
(B) 25 cm
(C) 35 cm
(D) 45 cm
Q12. Myopia can be corrected by using:
(A) convex lens
(B) concave lens
(C) bifocal lens
(D) cylindrical lens
Q13. White light is composed of _______ colors.
(A) 5
(B) 6
(C) 7
(D) 8
Q14. The splitting of white light is called:
(A) reflection
(B) refraction
(C) dispersion
(D) scattering
Q15. The sky appears blue due to:
(A) reflection
(B) refraction
(C) dispersion
(D) scattering
Q16. If angle of incidence is 30°, what is the angle of reflection?
(A) 15°
(B) 30°
(C) 60°
(D) 90°
Q17. The focal length of a convex mirror is always:
(A) positive
(B) negative
(C) zero
(D) infinity
Q18. If R = 20 cm for a concave mirror, then f = ?
(A) 40 cm
(B) 20 cm
(C) 10 cm
(D) 5 cm
Q19. Convex mirrors are used in vehicles as rear-view mirrors because they:
(A) form magnified images
(B) form real images
(C) give wider field of view
(D) are cheaper
Q20. The refractive index is the ratio of:
(A) sin r to sin i
(B) sin i to sin r
(C) cos i to cos r
(D) tan i to tan r
Q21. If the refractive index of water is 1.33, speed of light in water is:
(A) 1.33 × 10⁸ m/s
(B) 2.25 × 10⁸ m/s
(C) 3 × 10⁸ m/s
(D) 4 × 10⁸ m/s
Q22. A concave lens always forms:
(A) real images
(B) virtual images
(C) inverted images
(D) magnified images
Q23. Power of a lens is 2 D. Its focal length is:
(A) 2 m
(B) 0.5 m
(C) 50 cm
(D) Both (B) and (C)
Q24. The eye lens is:
(A) concave
(B) convex
(C) plane
(D) cylindrical
Q25. Hypermetropia is corrected by:
(A) concave lens
(B) convex lens
(C) plane mirror
(D) concave mirror
Q26. Presbyopia occurs due to:
(A) elongation of eyeball
(B) shortening of eyeball
(C) weakening of ciliary muscles
(D) damage to retina
Q27. Which color has the longest wavelength?
(A) violet
(B) blue
(C) green
(D) red
Q28. Stars twinkle due to:
(A) atmospheric refraction
(B) atmospheric reflection
(C) scattering
(D) dispersion
Q29. Planets do not twinkle because they:
(A) are closer to earth
(B) are farther from earth
(C) do not emit light
(D) are smaller in size
Q30. Sun appears red at sunrise and sunset due to:
(A) scattering of red light
(B) scattering of blue light
(C) reflection of red light
(D) refraction of red light
Q31. An object is placed at the focus of a concave mirror. The image formed is:
(A) at the focus
(B) at infinity
(C) at the pole
(D) at center of curvature
Q32. For a convex mirror, magnification is always:
(A) greater than 1
(B) less than 1 and positive
(C) less than 1 and negative
(D) equal to 1
Q33. If focal length of a spherical mirror is 15 cm, its radius of curvature is:
(A) 7.5 cm
(B) 15 cm
(C) 30 cm
(D) 45 cm
Q34. Light ray parallel to principal axis of concave mirror passes through _______ after reflection.
(A) pole
(B) center of curvature
(C) focus
(D) infinity
Q35. An object is placed between pole and focus of concave mirror. Image formed is:
(A) real and inverted
(B) real and erect
(C) virtual and inverted
(D) virtual and erect
Q36. The absolute refractive index of a medium is always:
(A) less than 1
(B) greater than or equal to 1
(C) equal to 1
(D) negative
Q37. When light passes from denser to rarer medium, it bends:
(A) towards the normal
(B) away from the normal
(C) along the normal
(D) does not bend
Q38. If refractive index of glass is 1.5, critical angle for total internal reflection is approximately:
(A) 30°
(B) 42°
(C) 60°
(D) 48°
Q39. A convex lens of focal length 20 cm forms real image when object is placed:
(A) at 10 cm
(B) at 15 cm
(C) at 25 cm
(D) All of the above
Q40. Power of combination of two lenses of power +2D and -1D is:
(A) +3D
(B) +1D
(C) -1D
(D) +2D
Q41. The power of accommodation of human eye is due to:
(A) cornea
(B) iris
(C) eye lens and ciliary muscles
(D) retina
Q42. A myopic person has far point at 2 m. Power of corrective lens needed is:
(A) +0.5 D
(B) -0.5 D
(C) +2 D
(D) -2 D
Q43. A hypermetropic person has near point at 50 cm. Power of corrective lens is:
(A) +1 D
(B) +2 D
(C) +3 D
(D) +4 D
Q44. The phenomenon of dispersion shows that white light:
(A) is a pure color
(B) is mixture of seven colors
(C) cannot be split
(D) has no color
Q45. Which color deviates least in dispersion by prism?
(A) violet
(B) blue
(C) green
(D) red
Q46. Rainbow is formed due to:
(A) dispersion only
(B) total internal reflection only
(C) both dispersion and total internal reflection
(D) scattering
Q47. The sun is visible about 2 minutes before actual sunrise due to:
(A) scattering
(B) atmospheric refraction
(C) dispersion
(D) reflection
Q48. Scattering of light is inversely proportional to:
(A) λ²
(B) λ³
(C) λ⁴
(D) λ
Q49. Clouds appear white because:
(A) they scatter all colors equally
(B) they absorb all colors
(C) they reflect only white light
(D) they are made of ice
Q50. The danger signals are red because:
(A) red light travels faster
(B) red light is scattered least
(C) red light is brightest
(D) red light has highest energy
Q51. An object 4 cm tall is placed 15 cm away from concave mirror of focal length 10 cm. The image height is:
(A) 6 cm
(B) 8 cm
(C) 10 cm
(D) 12 cm
Q52. For the above question, the image distance is:
(A) 20 cm
(B) 25 cm
(C) 30 cm
(D) 35 cm
Q53. A convex mirror of focal length 20 cm forms image of object placed 30 cm away. Image distance is:
(A) 10 cm
(B) 12 cm
(C) 15 cm
(D) 18 cm
Q54. Light travels from air to glass with refractive index 1.5. If angle of incidence is 60°, angle of refraction is approximately:
(A) 30°
(B) 35°
(C) 40°
(D) 45°
Q55. Speed of light in diamond (μ = 2.42) is:
(A) 1.24 × 10⁸ m/s
(B) 1.50 × 10⁸ m/s
(C) 2.25 × 10⁸ m/s
(D) 2.42 × 10⁸ m/s
Q56. An object is placed 25 cm from convex lens of focal length 15 cm. The image distance is:
(A) 37.5 cm
(B) 30 cm
(C) 45 cm
(D) 40 cm
Q57. For the above question (Q56), magnification is:
(A) -1.5
(B) +1.5
(C) -2.5
(D) +2.5
Q58. A lens has power -4 D. An object placed 30 cm away will form image at:
(A) 15 cm same side
(B) 18.75 cm same side
(C) 20 cm same side
(D) 25 cm same side
Q59. Two thin lenses of focal lengths 20 cm and 25 cm are in contact. The focal length of combination is:
(A) 45 cm
(B) 22.5 cm
(C) 11.11 cm
(D) 2.5 cm
Q60. The power of accommodation of normal human eye is about:
(A) 1 D
(B) 4 D
(C) 10 D
(D) 64 D
Q61. A person cannot see objects closer than 40 cm. The power of lens required to see at 25 cm is:
(A) +1.5 D
(B) +2.5 D
(C) +3.5 D
(D) +4.5 D
Q62. A myopic person can see clearly up to 1.2 m. The focal length of corrective lens is:
(A) -1.2 m
(B) +1.2 m
(C) -0.83 m
(D) +0.83 m
Q63. The refractive index of violet light in glass is 1.665 and for red light is 1.635. The ratio of speeds is:
(A) 1.018
(B) 0.982
(C) 1.5
(D) 2.0
Q64. A prism deviates red light by 42° and violet light by 48°. The angular dispersion is:
(A) 42°
(B) 48°
(C) 6°
(D) 90°
Q65. The apparent depth of a swimming pool is 3 m. If refractive index of water is 4/3, actual depth is:
(A) 2.25 m
(B) 4 m
(C) 3.75 m
(D) 5 m
Q66. A star appears higher than its actual position by maximum angle of:
(A) 15'
(B) 30'
(C) 35'
(D) 45'
Q67. The wavelength of blue light in air is 480 nm. Its wavelength in glass (μ = 1.5) is:
(A) 320 nm
(B) 360 nm
(C) 480 nm
(D) 720 nm
Q68. If the sun appears for 4 minutes extra due to atmospheric refraction, sunrise appears early by:
(A) 1 minute
(B) 2 minutes
(C) 3 minutes
(D) 4 minutes
Q69. For Rayleigh scattering, the intensity of scattered light is proportional to:
(A) 1/λ²
(B) 1/λ⁴
(C) λ²
(D) λ⁴
Q70. The ratio of scattering of blue to red light is approximately:
(A) 2:1
(B) 4:1
(C) 5:1
(D) 9:1
Q71. A concave mirror of focal length 15 cm forms real image twice the size of object. Object distance is:
(A) 20 cm
(B) 22.5 cm
(C) 25 cm
(D) 30 cm
Q72. An object is placed between two plane mirrors inclined at 60°. Number of images formed is:
(A) 4
(B) 5
(C) 6
(D) 7
Q73. A ray travels from medium 1 (μ₁ = 1.2) to medium 2 (μ₂ = 1.8). For total internal reflection, angle of incidence should be greater than:
(A) 30°
(B) 42°
(C) 48°
(D) 60°
Q74. A convex lens of focal length 20 cm is cut into two halves. The focal length of each half is:
(A) 10 cm
(B) 20 cm
(C) 40 cm
(D) 5 cm
Q75. Two convex lenses of focal lengths 10 cm and 15 cm are separated by 30 cm. For parallel incident beam, image is formed at:
(A) 15 cm from second lens
(B) 20 cm from second lens
(C) 6 cm from second lens
(D) 12 cm from second lens
Q76. A person can see objects from 15 cm to 2.5 m clearly. The powers of near and far vision corrective lenses are:
(A) +2.67 D, -0.4 D
(B) -2.67 D, +0.4 D
(C) +2.67 D, +0.4 D
(D) -2.67 D, -0.4 D
Q77. A glass slab of thickness 6 cm and refractive index 1.5 produces lateral displacement of:
(A) 2 cm
(B) 4 cm
(C) 1 cm
(D) depends on angle of incidence
Q78. The minimum deviation for equilateral prism is 37°. The refractive index of material is:
(A) 1.41
(B) 1.5
(C) 1.52
(D) 1.6
Q79. A fish appears at depth 40 cm below water surface. Its actual depth is: (μ_water = 4/3)
(A) 30 cm
(B) 53.33 cm
(C) 45 cm
(D) 60 cm
Q80. A microscope has objective lens of focal length 1 cm and eyepiece of focal length 5 cm separated by 20 cm. Magnifying power for relaxed eye is:
(A) 100
(B) 75
(C) 70
(D) 50
Q81. The power of combination of three lenses +2D, -1D, and +0.5D placed in contact is:
(A) +1.5 D
(B) -1.5 D
(C) +3.5 D
(D) -0.5 D
Q82. A telescope has objective of focal length 100 cm and eyepiece of focal length 5 cm. Its magnifying power is:
(A) 20
(B) 25
(C) 30
(D) 105
Q83. The critical angle for diamond-air interface is approximately: (μ_diamond = 2.42)
(A) 20°
(B) 24°
(C) 30°
(D) 42°
Q84. For a symmetric biconvex lens with radii R₁ = +20 cm and R₂ = -20 cm in air, if μ = 1.5, focal length is:
(A) 15 cm
(B) 20 cm
(C) 25 cm
(D) 30 cm
Q85. The dispersive power of crown glass is 0.02. For mean deviation 40°, angular dispersion is:
(A) 0.5°
(B) 0.8°
(C) 1.0°
(D) 2.0°
Q86. A virtual object is placed 10 cm in front of concave mirror of focal length 15 cm. The image distance is:
(A) 30 cm behind mirror
(B) 6 cm behind mirror
(C) 30 cm in front of mirror
(D) 6 cm in front of mirror
Q87. A ray incident at angle i on one face of prism of angle A emerges at angle e. The ray inside prism makes angle r₁ and r₂ with normals. Which is correct?
(A) i + e = A + δ
(B) r₁ + r₂ = A
(C) δ = i + e - A
(D) All of above
Q88. An equiconvex lens has focal length 20 cm in air. When immersed in liquid of refractive index 1.25, focal length becomes:
(A) 40 cm
(B) 60 cm
(C) 80 cm
(D) 100 cm
Q89. A double convex lens made of glass (μ = 1.5) has radii 20 cm and 30 cm. Its power in air is:
(A) +4.17 D
(B) -4.17 D
(C) +2.4 D
(D) +8.33 D
Q90. A ray undergoes minimum deviation in equilateral prism. If refractive index is √3, the angle of incidence is:
(A) 30°
(B) 45°
(C) 60°
(D) 75°
Q91. Huygen's principle is used to explain:
(A) reflection only
(B) refraction only
(C) both reflection and refraction
(D) interference
Q92. A beaker contains water up to height 20 cm. The apparent height when viewed from top is: (μ = 4/3)
(A) 15 cm
(B) 26.67 cm
(C) 25 cm
(D) 13.33 cm
Q93. The phenomenon responsible for the blue color of ocean water is:
(A) reflection of sky
(B) scattering by water molecules
(C) absorption of red light
(D) total internal reflection
Q94. For a lens to behave as diverging lens in all media, it should be made of material having:
(A) highest refractive index
(B) lowest refractive index
(C) moderate refractive index
(D) variable refractive index
Q95. If a convex lens forms real image of same size as object, the object must be placed at:
(A) F
(B) 2F
(C) between F and 2F
(D) beyond 2F
Q96. A ray of light passes through equilateral prism such that angle of incidence equals angle of emergence. If angle of incidence is 45°, deviation is:
(A) 15°
(B) 30°
(C) 45°
(D) 60°
Q97. The resolving power of human eye is about:
(A) 1°
(B) 1'
(C) 1"
(D) 0.1'
Q98. If aperture of concave mirror is increased, its focal length:
(A) increases
(B) decreases
(C) remains same
(D) becomes zero
Q99. Two identical equiconvex lenses are placed in contact. If focal length of each is 20 cm, power of combination is:
(A) +5 D
(B) +10 D
(C) +2.5 D
(D) +20 D
Q100. A person looking at mesh of crossed wires is able to see the vertical wires clearly but horizontal wires appear blurred. This defect is:
(A) myopia
(B) hypermetropia
(C) astigmatism
(D) presbyopia