Light Reflection and Refraction

1. What is the principal focus of a concave mirror?
  a) The point where parallel rays converge
  b) The point where rays diverge
  c) The point where the mirror is curved
  d) The center of curvature
  Answer: a) The point where parallel rays converge
2. The radius of curvature of a spherical mirror is 20 cm. What is its focal length?
  a) 5 cm
  b) 10 cm
  c) 20 cm
  d) 40 cm
  Answer: b) 10 cm
3. Which mirror always forms a virtual, erect, and diminished image?
  a) Plane mirror
  b) Convex mirror
  c) Concave mirror
  d) Spherical mirror
  Answer: b) Convex mirror
4. In a concave mirror, where should the object be placed to get an enlarged virtual image?
  a) Beyond the center of curvature
  b) At the principal focus
  c) Between the focus and the pole
  d) At the center of curvature
  Answer: c) Between the focus and the pole
5. The refractive index of a medium determines:
  a) The reflection angle
  b) The speed of light in the medium
  c) The type of lens used
  d) The density of the medium
  Answer: b) The speed of light in the medium
6. What type of image does a convex mirror form for all object positions?
  a) Real and inverted
  b) Virtual and erect
  c) Enlarged and virtual
  d) Diminished and real
  Answer: b) Virtual and erect
7. If the focal length of a convex lens is 10 cm, what is its power in dioptres?
  a) +10 D
  b) +0.1 D
  c) +1 D
  d) +5 D
  Answer: a) +10 D
8. Which mirror is used in the headlights of vehicles?
  a) Plane mirror
  b) Concave mirror
  c) Convex mirror
  d) Spherical mirror
  Answer: b) Concave mirror
9. What happens when light travels from a rarer medium to a denser medium?
  a) It bends towards the normal
  b) It bends away from the normal
  c) It travels without deviation
  d) It gets reflected
  Answer: a) It bends towards the normal
10. A virtual image larger than the object can be obtained using a:
  a) Concave mirror
  b) Convex mirror
  c) Plane mirror
  d) Convex lens
  Answer: a) Concave mirror
11. Which lens is thicker at the middle and thinner at the edges?
  a) Concave lens
  b) Convex lens
  c) Cylindrical lens
  d) Plane lens
  Answer: b) Convex lens
12. The magnification produced by a plane mirror is:
  a) Less than 1
  b) More than 1
  c) Exactly 1
  d) Zero
  Answer: c) Exactly 1
13. What is the formula for magnification in mirrors?
  a)
  M=hh′M = \frac{h}{h’}
  $M = h ^{'} h$
  b)
  M=−vuM = \frac{-v}{u}
  $M = u - v$
  c)
  M=uvM = \frac{u}{v}
  $M = v u$
  d)
  M=vuM = \frac{v}{u}
  $M = u v$
  Answer: b)
  
  M=−vuM = \frac{-v}{u}
  
  $M = u - v$
14. If the object distance for a concave mirror is 10 cm, and its focal length is 5 cm, where will the image be formed?
  a) 20 cm
  b) 10 cm
  c) 5 cm
  d) 2.5 cm
  Answer: a) 20 cm
15. Which lens is used in magnifying glasses?
  a) Concave lens
  b) Convex lens
  c) Cylindrical lens
  d) Diverging lens
  Answer: b) Convex lens
16. The absolute refractive index of diamond is 2.42. What does this mean?
  a) Speed of light in diamond is 2.42 times faster than air
  b) Speed of light in air is 2.42 times faster than in diamond
  c) Diamond bends light away from the normal
  d) Diamond is optically less dense than air
  Answer: b) Speed of light in air is 2.42 times faster than in diamond
17. The focal length of a concave mirror is negative because:
  a) It forms virtual images
  b) The focal point lies behind the mirror
  c) The focal point lies on the same side as the object
  d) It forms inverted images
  Answer: c) The focal point lies on the same side as the object
18. The emergent ray in a glass slab is:
  a) Parallel to the incident ray
  b) Divergent from the incident ray
  c) Convergent to the incident ray
  d) At an angle to the incident ray
  Answer: a) Parallel to the incident ray
19. A lens with a power of -2.5 D is:
  a) Concave
  b) Convex
  c) Cylindrical
  d) Plane
  Answer: a) Concave
20. If the object is placed at infinity in front of a convex lens, where is the image formed?
  a) At the focus, highly diminished
  b) At the optical center
  c) At twice the focal length
  d) At infinity, enlarged
  Answer: a) At the focus, highly diminished
21. The focal length of a mirror is related to its radius of curvature by:
  a)
  f=2Rf = 2R
  $f = 2 R$
  b)
  f=R2f = \frac{R}{2}
  $f = 2 R$
  c)
  f=Rf = R
  $f = R$
  d)
  f=1Rf = \frac{1}{R}
  $f = R 1$
  Answer: b)
  
  f=R2f = \frac{R}{2}
  
  $f = 2 R$
22. What type of lens is used in spectacles for correcting myopia?
  a) Convex lens
  b) Concave lens
  c) Cylindrical lens
  d) Plane lens
  Answer: b) Concave lens
23. What is the unit of the power of a lens?
  a) Metres
  b) Dioptre
  c) Newton
  d) Joule
  Answer: b) Dioptre
24. In a concave mirror, if the object is placed at the center of curvature, the image will be:
  a) Real, inverted, and same size
  b) Virtual, erect, and enlarged
  c) Real, inverted, and diminished
  d) Virtual, inverted, and magnified
  Answer: a) Real, inverted, and same size
25. The speed of light in water is slower than in air because:
  a) Water absorbs more light
  b) Water is optically denser
  c) Light bends towards the normal
  d) Water is a liquid
  Answer: b) Water is optically denser
26. The image formed by a convex mirror is always:
  a) Virtual and diminished
  b) Real and diminished
  c) Virtual and enlarged
  d) Real and inverted
  Answer: a) Virtual and diminished
27. Which of the following follows the law of reflection?
  a) Plane mirrors only
  b) Curved mirrors only
  c) Both plane and curved mirrors
  d) Transparent surfaces only
  Answer: c) Both plane and curved mirrors
28. What is the magnification of an image formed by a plane mirror?
  a) Less than 1
  b) Equal to 1
  c) More than 1
  d) Cannot be determined
  Answer: b) Equal to 1
29. A concave mirror forms a virtual and magnified image when the object is placed:
  a) Beyond the center of curvature
  b) Between focus and the pole
  c) At the center of curvature
  d) At the principal focus
  Answer: b) Between focus and the pole
30. When light passes from air to glass, its speed:
  a) Increases
  b) Decreases
  c) Remains the same
  d) Becomes infinite
  Answer: b) Decreases
31. What type of lens is used in a microscope to magnify small objects?
  a) Concave lens
  b) Convex lens
  c) Cylindrical lens
  d) Plane lens
  Answer: b) Convex lens
32. The unit of refractive index is:
  a) Metres per second
  b) Dioptre
  c) No unit
  d) Newton per metre
  Answer: c) No unit
33. What is the nature of an image formed by a concave lens?
  a) Virtual, erect, and diminished
  b) Virtual, inverted, and diminished
  c) Real, erect, and magnified
  d) Real, inverted, and diminished
  Answer: a) Virtual, erect, and diminished
34. The mirror formula is given by:
  a)
  1f=1v−1u\frac{1}{f} = \frac{1}{v} – \frac{1}{u}
  $f 1 = v 1 - u 1$
  b)
  1f=1v+1u\frac{1}{f} = \frac{1}{v} + \frac{1}{u}
  $f 1 = v 1 + u 1$
  c)
  f=v+uf = v + u
  $f = v + u$
  d)
  f=v−u2f = \frac{v – u}{2}
  $f = 2 v - u$
  Answer: b)
  1f=1v+1u\frac{1}{f} = \frac{1}{v} + \frac{1}{u}
  $f 1 = v 1 + u 1$
35. When light bends as it passes from one medium to another, the phenomenon is called:
  a) Reflection
  b) Refraction
  c) Diffraction
  d) Dispersion
  Answer: b) Refraction
36. A lens that diverges light rays is called:
  a) Convex lens
  b) Concave lens
  c) Converging lens
  d) Cylindrical lens
  Answer: b) Concave lens
37. The formula for the power of a lens is:
  a)
  P=1fP = \frac{1}{f}
  $P = f 1$ (f in metres)
  b)
  P=f2P = f^2
  $P = f^{2}$
  c)
  P=2fP = 2f
  $P = 2 f$
  d)
  P=1f2P = \frac{1}{f^2}
  $P = f ^{2} 1$
  Answer: a)
  P=1fP = \frac{1}{f}
  $P = f 1$ (f in metres)
38. A convex mirror is preferred as a rear-view mirror in vehicles because:
  a) It forms real images
  b) It provides a wider field of view
  c) It magnifies the image
  d) It forms inverted images
  Answer: b) It provides a wider field of view
39. The image formed by a convex lens when the object is placed at infinity is:
  a) Real, inverted, and highly diminished
  b) Virtual, erect, and magnified
  c) Real, inverted, and enlarged
  d) Virtual, inverted, and diminished
  Answer: a) Real, inverted, and highly diminished
40. The speed of light in vacuum is:
  a)
  3×108 m/s3 \times 10^8 \, \text{m/s}
  $3 \times 1 0^{8} m/s$
  b)
  3×106 m/s3 \times 10^6 \, \text{m/s}
  $3 \times 1 0^{6} m/s$
  c)
  3×104 m/s3 \times 10^4 \, \text{m/s}
  $3 \times 1 0^{4} m/s$
  d)
  3×1010 m/s3 \times 10^{10} \, \text{m/s}
  $3 \times 1 0^{10} m/s$
  Answer: a)
  3×108 m/s3 \times 10^8 \, \text{m/s}
  $3 \times 1 0^{8} m/s$
41. A lens with a focal length of -20 cm is:
  a) A convex lens
  b) A concave lens
  c) A plane lens
  d) A cylindrical lens
  Answer: b) A concave lens
42. In which medium does light travel the fastest?
  a) Air
  b) Water
  c) Glass
  d) Diamond
  Answer: a) Air
43. The point where all parallel rays converge after reflection in a concave mirror is:
  a) Pole
  b) Focus
  c) Center of curvature
  d) Principal axis
  Answer: b) Focus
44. A lens has a power of +2D. What is its focal length?
  a) 2 m
  b) 0.5 m
  c) 50 cm
  d) 2.5 m
  Answer: b) 0.5 m
45. A dentist uses which type of mirror to view an enlarged image of teeth?
  a) Plane mirror
  b) Convex mirror
  c) Concave mirror
  d) Spherical mirror
  Answer: c) Concave mirror
46. When light passes through a prism, it splits into:
  a) Two colors
  b) Seven colors
  c) Infinite colors
  d) A single beam
  Answer: b) Seven colors
47. A virtual image larger than the object can be produced by:
  a) A convex mirror
  b) A concave mirror
  c) A concave lens
  d) A plane mirror
  Answer: b) A concave mirror
48. The property of light that explains the formation of a rainbow is:
  a) Reflection
  b) Refraction
  c) Dispersion
  d) Diffraction
  Answer: c) Dispersion
49. For a concave mirror, the focal length is:
  a) Positive
  b) Negative
  c) Zero
  d) Undefined
  Answer: b) Negative
50. What kind of image is formed by a plane mirror?
  a) Real, inverted, and same size
  b) Virtual, erect, and same size
  c) Real, inverted, and diminished
  d) Virtual, erect, and enlarged
  Answer: b) Virtual, erect, and same size
51. What happens to light when it travels from a denser medium to a rarer medium?
  a) It bends towards the normal
  b) It bends away from the normal
  c) It remains undeviated
  d) It reflects back
  Answer: b) It bends away from the normal
52. What is the principal axis of a spherical mirror?
  a) A line joining the pole and the focus
  b) A line joining the pole and the center of curvature
  c) A line passing through the focus and normal to the mirror
  d) A line passing through the pole and center of curvature
  Answer: d) A line passing through the pole and center of curvature
53. A convex lens has a focal length of 25 cm. Its power is:
  a) +4 D
  b) +2.5 D
  c) +1 D
  d) +0.25 D
  Answer: b) +2.5 D
54. What kind of mirror is used as a shaving mirror?
  a) Plane mirror
  b) Convex mirror
  c) Concave mirror
  d) Spherical mirror
  Answer: c) Concave mirror
55. The center of curvature of a convex mirror lies:
  a) Behind the mirror
  b) In front of the mirror
  c) At the focal point
  d) On the surface of the mirror
  Answer: a) Behind the mirror
56. Which of the following lenses always forms a virtual image?
  a) Concave lens
  b) Convex lens
  c) Cylindrical lens
  d) Plane lens
  Answer: a) Concave lens
57. If the object is placed at the focus of a concave mirror, the image will be:
  a) At the pole
  b) At infinity
  c) At the center of curvature
  d) Between the pole and focus
  Answer: b) At infinity
58. The refractive index of glass is higher than that of water because:
  a) Glass is denser than water
  b) Light travels faster in glass than in water
  c) Glass bends light more than water
  d) Water reflects light better than glass
  Answer: c) Glass bends light more than water
59. What type of image is formed when light rays actually meet at a point after reflection or refraction?
  a) Virtual image
  b) Erect image
  c) Real image
  d) Diminished image
  Answer: c) Real image
60. What is the formula for the refractive index of a medium?
  a) $\frac{v}{c}$
  b) $\frac{c}{v}$
  c) $\times v$
  d) $\frac{1}{v}$
  Answer: b) $\frac{c}{v}$
61. A convex mirror always forms:
  a) A real and diminished image
  b) A virtual and erect image
  c) A virtual and magnified image
  d) A real and enlarged image
  Answer: b) A virtual and erect image
62. Which phenomenon is responsible for the twinkling of stars?
  a) Reflection
  b) Refraction
  c) Dispersion
  d) Scattering
  Answer: b) Refraction
63. A real image is always:
  a) Erect
  b) Inverted
  c) Magnified
  d) Virtual
  Answer: b) Inverted
64. A ray of light passes through the optical center of a lens. It:
  a) Bends towards the principal axis
  b) Bends away from the principal axis
  c) Passes undeviated
  d) Reflects back
  Answer: c) Passes undeviated
65. The distance between the pole and the focus of a mirror is called:
  a) Principal axis
  b) Focal length
  c) Radius of curvature
  d) Aperture
  Answer: b) Focal length
66. Which lens is used to correct hypermetropia (far-sightedness)?
  a) Concave lens
  b) Convex lens
  c) Cylindrical lens
  d) Bifocal lens
  Answer: b) Convex lens
67. What happens when parallel rays of light pass through a convex lens?
  a) They diverge
  b) They converge at the focus
  c) They remain parallel
  d) They reflect back
  Answer: b) They converge at the focus
68. A ray of light incident at an angle of 90° on the surface of a glass slab will:
  a) Bend towards the normal
  b) Bend away from the normal
  c) Pass undeviated
  d) Reflect completely
  Answer: c) Pass undeviated
69. A lens with a power of -1.5 D is used for:
  a) Myopia correction
  b) Hypermetropia correction
  c) Astigmatism correction
  d) Presbyopia correction
  Answer: a) Myopia correction
70. Which of the following materials has the highest refractive index?
  a) Water
  b) Glass
  c) Diamond
  d) Air
  Answer: c) Diamond
71. The focal length of a plane mirror is:
  a) Infinity
  b) Zero
  c) One
  d) Negative
  Answer: a) Infinity
72. The power of a lens is measured in:
  a) Metres
  b) Dioptres
  c) Centimetres
  d) Joules
  Answer: b) Dioptres
73. A concave lens always forms an image that is:
  a) Real and inverted
  b) Virtual and erect
  c) Magnified and real
  d) Erect and real
  Answer: b) Virtual and erect
74. The splitting of white light into its constituent colors is called:
  a) Refraction
  b) Dispersion
  c) Diffraction
  d) Reflection
  Answer: b) Dispersion
75. The mirror used in solar furnaces is:
  a) Plane mirror
  b) Convex mirror
  c) Concave mirror
  d) Cylindrical mirror
  Answer: c) Concave mirror
76. What happens to the image when an object is placed between the optical center and focus of a convex lens?
  a) Real, inverted, and magnified
  b) Virtual, erect, and magnified
  c) Virtual, erect, and diminished
  d) Real, inverted, and diminished
  Answer: b) Virtual, erect, and magnified
77. The distance between the optical center and the focus of a lens is its:
  a) Aperture
  b) Radius of curvature
  c) Focal length
  d) Principal axis
  Answer: c) Focal length
78. The magnification of a virtual image is always:
  a) Positive
  b) Negative
  c) Zero
  d) Undefined
  Answer: a) Positive
79. Which lens is thicker at the edges and thinner at the center?
  a) Convex lens
  b) Concave lens
  c) Plane lens
  d) Cylindrical lens
  Answer: b) Concave lens
80. What is the nature of the image formed by a convex lens when the object is at infinity?
  a) Real and inverted
  b) Virtual and erect
  c) Real and magnified
  d) Virtual and diminished
  Answer: a) Real and inverted
81. A real image can be obtained on:
  a) A screen
  b) A plane mirror
  c) A convex mirror
  d) A concave lens
  Answer: a) A screen
82. Which property of light is responsible for the formation of shadows?
  a) Reflection
  b) Refraction
  c) Straight-line propagation
  d) Diffraction
  Answer: c) Straight-line propagation
83. A lens with a focal length of -50 cm is:
  a) A convex lens
  b) A concave lens
  c) A plane lens
  d) A cylindrical lens
  Answer: b) A concave lens
84. The mirror formula is used to find:
  a) The position of the object
  b) The focal length of the mirror
  c) The position of the image
  d) All of the above
  Answer: d) All of the above
85. The angle of incidence is equal to the angle of reflection according to:
  a) Law of refraction
  b) Law of dispersion
  c) Law of reflection
  d) Snell’s law
  Answer: c) Law of reflection
86. The optical center of a lens is the point:
  a) Where light rays converge
  b) Through which light passes without deviation
  c) Where parallel rays meet
  d) None of the above
  Answer: b) Through which light passes without deviation
87. Which mirror can produce a magnified and inverted image?
  a) Plane mirror
  b) Convex mirror
  c) Concave mirror
  d) None of the above
  Answer: c) Concave mirror
88. The unit of magnification is:
  a) Metres
  b) Centimeters
  c) Dioptres
  d) Unitless
  Answer: d) Unitless
89. Light bends more in a medium with:
  a) Lower refractive index
  b) Higher refractive index
  c) Lower optical density
  d) None of the above
  Answer: b) Higher refractive index
90. Which type of image is always diminished in size?
  a) Real image
  b) Virtual image
  c) Convex mirror image
  d) Concave mirror image
  Answer: c) Convex mirror image
91. A concave mirror is used in torches because:
  a) It spreads light
  b) It converges light into a beam
  c) It magnifies the image
  d) It reflects all colors equally
  Answer: b) It converges light into a beam
92. The refractive index of a material depends on:
  a) Speed of light in vacuum only
  b) Speed of light in that material
  c) Both a and b
  d) None of the above
  Answer: c) Both a and b
93. A convex lens forms a virtual and enlarged image when the object is placed:
  a) At infinity
  b) At the focal point
  c) Between the optical center and focus
  d) Beyond the focal point
  Answer: c) Between the optical center and focus
94. Light passing through a prism undergoes:
  a) Reflection only
  b) Refraction only
  c) Refraction and dispersion
  d) Reflection and diffraction
  Answer: c) Refraction and dispersion
95. The size of the image formed by a plane mirror is:
  a) Smaller than the object
  b) Larger than the object
  c) Equal to the object
  d) Variable
  Answer: c) Equal to the object
96. The power of a lens is the reciprocal of:
  a) Aperture
  b) Radius of curvature
  c) Focal length
  d) Magnification
  Answer: c) Focal length
97. The radius of curvature of a spherical mirror is twice its:
  a) Magnification
  b) Principal axis
  c) Focal length
  d) Aperture
  Answer: c) Focal length
98. What is the focal length of a convex lens of power +5 D?
  a) 0.5 m
  b) 5 m
  c) 20 m
  d) 2.5 m
  Answer: a) 0.5 m
99. A lens used to concentrate sunlight is:
  a) Concave lens
  b) Convex lens
  c) Cylindrical lens
  d) Plane lens
  Answer: b) Convex lens
100. When light passes through a rectangular glass slab, the emergent ray is:
  a) Perpendicular to the incident ray
  b) Parallel to the incident ray
  c) At an angle to the incident ray
  d) Refracted twice
  Answer: b) Parallel to the incident ray