CLASS 10 CHAPTER 9 LIGHT REFLECTION AND REFRACTION MCQs
1. What does light help us to do during the day?
(A) See objects
(B) Make objects disappear
(C) Change the color of objects
(D) Create shadows
Answer
Answer: (A) See objects
2. What happens when light falls on an object?
(A) The object absorbs all light
(B) The object emits light
(C) The object reflects light
(D) The object destroys light
Answer
Answer: (C) The object reflects light
3. What type of medium allows light to pass through and enables us to see through it?
(A) Opaque medium
(B) Transparent medium
(C) Reflective medium
(D) Absorptive medium
Answer
Answer: (B) Transparent medium
4. What is the straight-line path of light usually called?
(A) Wave
(B) Ray
(C) Beam
(D) Photon
Answer
Answer: (B) Ray
5. What is the effect called when light bends around a small object?
(A) Reflection
(B) Diffraction
(C) Refraction
(D) Interference
Answer
Answer: (B) Diffraction
6. Which theory reconciles both the wave and particle nature of light?
(A) Classical theory
(B) Quantum theory
(C) Wave theory
(D) Ray theory
Answer
Answer: (B) Quantum theory
7. Which mirror forms a virtual and erect image that is equal in size to the object?
(A) Concave mirror
(B) Convex mirror
(C) Plane mirror
(D) None of the above
Answer
Answer: (C) Plane mirror
8. What happens when light passes through a transparent medium?
(A) It gets absorbed
(B) It reflects back
(C) It transmits through
(D) It changes color
Answer
Answer: (C) It transmits through
9. What are the two laws of reflection of light?
(A) Angle of incidence is greater than angle of reflection; Rays always diverge
(B) Angle of incidence is equal to angle of reflection; Rays lie in the same plane
(C) Reflection depends on surface roughness; Rays scatter in different directions
(D) Reflection changes based on color; Incident ray disappears
Answer
Answer: (B) Angle of incidence is equal to angle of reflection; Rays lie in the same plane
10. Which type of image is always formed by a plane mirror?
(A) Real and inverted
(B) Virtual and erect
(C) Diminished and real
(D) Enlarged and real
Answer
Answer: (B) Virtual and erect
11. What type of mirror is the curved surface of a spoon similar to?
(A) Concave mirror
(B) Convex mirror
(C) Plane mirror
(D) Cylindrical mirror
Answer
Answer: (A) Concave mirror
12. What is the term used for the point where light rays parallel to the principal axis converge after reflection from a concave mirror?
(A) Centre of curvature
(B) Principal axis
(C) Pole
(D) Principal focus
Answer
Answer: (D) Principal focus
13. Which mirror is often used in torches and searchlights for producing powerful parallel beams of light?
(A) Convex mirror
(B) Concave mirror
(C) Plane mirror
(D) Cylindrical mirror
Answer
Answer: (B) Concave mirror
14. What is the distance between the pole and the principal focus of a spherical mirror called?
(A) Focal length
(B) Radius of curvature
(C) Principal distance
(D) Lateral distance
Answer
Answer: (A) Focal length
15. In which position does a concave mirror form a virtual and erect image?
(A) Between P and F
(B) At the focus F
(C) Beyond C
(D) At infinity
Answer
Answer: (A) Between P and F
16. Which type of image is formed when an object is placed between the pole and the focus of a concave mirror?
(A) Real and diminished
(B) Virtual and enlarged
(C) Real and inverted
(D) Virtual and inverted
Answer
Answer: (B) Virtual and enlarged
17. What happens to light rays when they pass from a rarer to a denser medium?
(A) They bend away from the normal
(B) They bend towards the normal
(C) They reflect completely
(D) They scatter in all directions
Answer
Answer: (B) They bend towards the normal
18. What is the refractive index of a medium?
(A) The ratio of the speed of light in vacuum to that in the medium
(B) The angle at which light bends in the medium
(C) The brightness of light in the medium
(D) The color change of light in different media
Answer
Answer: (A) The ratio of the speed of light in vacuum to that in the medium
19. What is the cause of refraction of light when it enters from one medium to another?
(A) Change in the direction of light
(B) Change in the speed of light
(C) Change in the wavelength of light
(D) Change in the intensity of light
Answer
Answer: (B) Change in the speed of light
20. What is the emergent ray in a rectangular glass slab?
(A) A ray parallel to the incident ray
(B) A ray perpendicular to the incident ray
(C) A ray refracted at 90 degrees
(D) A ray reflected back to the source
Answer
Answer: (A) A ray parallel to the incident ray
21. What happens when a ray of light passes from a denser medium to a rarer medium?
(A) It bends towards the normal
(B) It bends away from the normal
(C) It travels in a straight line
(D) It scatters into multiple rays
Answer
Answer: (B) It bends away from the normal
22. What is the SI unit of refractive index?
(A) Meter
(B) Second
(C) Dioptre
(D) It has no unit
Answer
Answer: (D) It has no unit
23. What is the optical density of a medium related to?
(A) Its mass density
(B) Its ability to reflect light
(C) Its refractive index
(D) Its color
Answer
Answer: (C) Its refractive index
24. Which material has the highest refractive index from the following options?
(A) Water
(B) Glass
(C) Diamond
(D) Air
Answer
Answer: (C) Diamond
25. What is the phenomenon of light bending when it passes from one medium to another called?
(A) Reflection
(B) Refraction
(C) Diffraction
(D) Dispersion
Answer
Answer: (B) Refraction
26. Which law governs the relationship between the angles of incidence and refraction?
(A) Law of Reflection
(B) Law of Diffraction
(C) Snell’s Law
(D) Newton’s Law
Answer
Answer: (C) Snell’s Law
27. What is the speed of light in a vacuum?
(A) 3 × 10^8 m/s
(B) 3 × 10^6 m/s
(C) 3 × 10^7 m/s
(D) 3 × 10^9 m/s
Answer
Answer: (A) 3 × 10^8 m/s
28. What happens to the speed of light as it passes from air to water?
(A) It increases
(B) It remains the same
(C) It decreases
(D) It stops
Answer
Answer: (C) It decreases
29. What does Snell’s law state about the ratio of the sine of the angle of incidence to the sine of the angle of refraction?
(A) It is equal to the speed of light
(B) It is a constant for the given media
(C) It equals the density of the medium
(D) It is always greater than 1
Answer
Answer: (B) It is a constant for the given media
30. Which of the following is an example of refraction?
(A) Formation of a shadow
(B) Bending of a pencil in water
(C) Reflection of light from a mirror
(D) Twinkling of stars
Answer
Answer: (B) Bending of a pencil in water
31. What is the refractive index of water?
(A) 1.00
(B) 1.33
(C) 1.50
(D) 1.77
Answer
Answer: (B) 1.33
32. Which medium allows light to travel the fastest?
(A) Water
(B) Glass
(C) Air
(D) Diamond
Answer
Answer: (C) Air
33. What does the refractive index indicate about a medium?
(A) Its optical density
(B) Its physical thickness
(C) Its temperature
(D) Its color
Answer
Answer: (A) Its optical density
34. What happens to a light ray when it passes through a glass slab and emerges on the other side?
(A) It travels in a different direction
(B) It continues parallel to its original path
(C) It refracts at 90 degrees
(D) It gets absorbed by the slab
Answer
Answer: (B) It continues parallel to its original path
35. Which of the following materials has the lowest refractive index?
(A) Diamond
(B) Water
(C) Air
(D) Glass
Answer
Answer: (C) Air
36. What is the relationship between the speed of light in air and the speed of light in a medium with a refractive index greater than 1?
(A) Light travels faster in the medium
(B) Light travels slower in the medium
(C) Light travels at the same speed
(D) Light does not travel through the medium
Answer
Answer: (B) Light travels slower in the medium
37. Which quantity is used to express the ability of a lens to converge or diverge light?
(A) Refractive index
(B) Power of the lens
(C) Focal length
(D) Aperture of the lens
Answer
Answer: (B) Power of the lens
38. What is the power of a lens if its focal length is 1 meter?
(A) 1 dioptre
(B) 2 dioptres
(C) 10 dioptres
(D) 0.5 dioptres
Answer
Answer: (A) 1 dioptre
39. A convex lens is also known as what type of lens?
(A) Diverging lens
(B) Converging lens
(C) Plane lens
(D) Cylindrical lens
Answer
Answer: (B) Converging lens
40. What is the principal focus of a convex lens?
(A) The point where parallel rays converge
(B) The center of the lens
(C) The midpoint between two surfaces
(D) The point where light rays diverge
Answer
Answer: (A) The point where parallel rays converge
41. What type of lens is thicker at the middle and thinner at the edges?
(A) Concave lens
(B) Convex lens
(C) Plane lens
(D) Cylindrical lens
Answer
Answer: (B) Convex lens
42. What happens when parallel rays of light pass through a convex lens?
(A) They diverge
(B) They converge at a point
(C) They reflect back
(D) They travel parallel to the principal axis
Answer
Answer: (B) They converge at a point
43. Which type of lens is known as a diverging lens?
(A) Concave lens
(B) Convex lens
(C) Cylindrical lens
(D) Plane lens
Answer
Answer: (A) Concave lens
44. Where is the principal focus of a concave lens located?
(A) In front of the lens
(B) At the center of the lens
(C) On the same side as the incident rays
(D) At the focal point behind the lens
Answer
Answer: (C) On the same side as the incident rays
45. What is the focal length of a lens?
(A) The distance between the pole and the object
(B) The distance between the center and the edge of the lens
(C) The distance between the principal focus and the optical center
(D) The distance between the object and the image
Answer
Answer: (C) The distance between the principal focus and the optical center
46. How can the focal length of a convex lens be found practically?
(A) By measuring the diameter of the lens
(B) By focusing parallel rays of light from the Sun on a sheet of paper
(C) By calculating the thickness of the lens
(D) By measuring the distance between the lens and the object
Answer
Answer: (B) By focusing parallel rays of light from the Sun on a sheet of paper
47. What is the distance between the two principal focuses of a lens called?
(A) Aperture
(B) Focal length
(C) Principal axis
(D) Radius of curvature
Answer
Answer: (C) Principal axis
48. What happens to parallel rays of light when they pass through a concave lens?
(A) They converge at a point
(B) They continue in the same direction
(C) They diverge from a point
(D) They reflect back
Answer
Answer: (C) They diverge from a point
49. What type of image is formed by a convex lens when the object is placed at infinity?
(A) Enlarged and real
(B) Highly diminished and real
(C) Virtual and erect
(D) Diminished and virtual
Answer
Answer: (B) Highly diminished and real
50. When an object is placed between the focal point and a convex lens, what type of image is formed?
(A) Real and inverted
(B) Virtual and erect
(C) Real and diminished
(D) Enlarged and real
Answer
Answer: (B) Virtual and erect
51. What is the nature of the image formed by a concave lens?
(A) Real and erect
(B) Virtual and enlarged
(C) Virtual and diminished
(D) Real and inverted
Answer
Answer: (C) Virtual and diminished
52. What happens when light rays pass through the optical center of a lens?
(A) They bend sharply
(B) They converge at a point
(C) They pass without deviation
(D) They reflect back
Answer
Answer: (C) They pass without deviation
53. Which of the following rays pass parallel to the principal axis after refraction through a convex lens?
(A) A ray passing through the focal point
(B) A ray passing through the optical center
(C) A ray parallel to the principal axis
(D) A diverging ray
Answer
Answer: (A) A ray passing through the focal point
54. What happens to light rays that are parallel to the principal axis after passing through a concave lens?
(A) They converge at a point
(B) They diverge as if coming from the principal focus
(C) They remain parallel
(D) They reflect back
Answer
Answer: (B) They diverge as if coming from the principal focus
55. When an object is placed at 2F of a convex lens, what is the nature of the image formed?
(A) Real, inverted, and same size
(B) Virtual, erect, and diminished
(C) Real, inverted, and enlarged
(D) Virtual, erect, and enlarged
Answer
Answer: (A) Real, inverted, and same size
56. What is the relationship between the magnification produced by a convex lens and the distance of the object from the lens?
(A) Magnification is always positive
(B) Magnification is the ratio of image distance to object distance
(C) Magnification is inversely proportional to object distance
(D) Magnification is the square of object distance
Answer
Answer: (B) Magnification is the ratio of image distance to object distance
57. What is the term for the distance between the focal point and the optical center of a lens?
(A) Radius of curvature
(B) Focal length
(C) Aperture
(D) Principal distance
Answer
Answer: (B) Focal length
58. When the object is placed at infinity in front of a concave lens, where is the image formed?
(A) At the focus
(B) At infinity
(C) Between the focus and the lens
(D) Behind the lens
Answer
Answer: (A) At the focus
59. What is the power of a lens with a focal length of 0.25 m?
(A) 4 D
(B) 2 D
(C) 1 D
(D) 0.5 D
Answer
Answer: (A) 4 D
60. What type of image does a concave lens always produce?
(A) Real and inverted
(B) Virtual and erect
(C) Diminished and inverted
(D) Real and enlarged
Answer
Answer: (B) Virtual and erect
61. Which of the following statements is true regarding the image formed by a convex lens?
(A) The image can be either real or virtual
(B) The image is always real and inverted
(C) The image is always virtual and erect
(D) The image is always diminished
Answer
Answer: (A) The image can be either real or virtual
62. If the object is placed at the focus of a convex lens, where will the image be formed?
(A) At infinity
(B) At the focal point
(C) Between the lens and focus
(D) At the center of the lens
Answer
Answer: (A) At infinity
63. What happens to the size of the image as the object moves closer to a convex lens from beyond 2F?
(A) The image becomes smaller
(B) The image remains the same size
(C) The image increases in size
(D) The image disappears
Answer
Answer: (C) The image increases in size
64. What is the formula for calculating the magnification produced by a lens?
(A) m = h’/h
(B) m = u/v
(C) m = v/u
(D) m = f/v
Answer
Answer: (C) m = v/u
65. What does the lens formula relate?
(A) Object distance, image distance, and the refractive index
(B) Object distance, image distance, and focal length
(C) Focal length and power of the lens
(D) Angle of incidence and angle of refraction
Answer
Answer: (B) Object distance, image distance, and focal length
66. Which of the following is the correct lens formula?
(A) 1/f = 1/v + 1/u
(B) 1/f = v + u
(C) 1/f = v – u
(D) 1/f = u + v
Answer
Answer: (A) 1/f = 1/v + 1/u
67. What does a positive magnification value indicate about an image?
(A) The image is real and inverted
(B) The image is virtual and erect
(C) The image is diminished
(D) The image is enlarged
Answer
Answer: (B) The image is virtual and erect
68. If the focal length of a lens is negative, what type of lens is it?
(A) Convex lens
(B) Concave lens
(C) Biconvex lens
(D) Biconcave lens
Answer
Answer: (B) Concave lens
69. What happens to the power of a lens as its focal length decreases?
(A) Power decreases
(B) Power increases
(C) Power remains the same
(D) Power becomes negative
Answer
Answer: (B) Power increases
70. What is the unit of power of a lens?
(A) Meter
(B) Dioptre
(C) Newton
(D) Kilogram
Answer
Answer: (B) Dioptre
71. What is the magnification produced when an object is placed at the focal point of a convex lens?
(A) 1
(B) 0
(C) Infinite
(D) Negative
Answer
Answer: (C) Infinite
72. In the case of lenses, what does the sign convention indicate for distances measured in the opposite direction of the incident light?
(A) They are considered positive
(B) They are considered negative
(C) They are always zero
(D) They can be both positive and negative
Answer
Answer: (B) They are considered negative
73. What is the significance of the principal axis in lens optics?
(A) It is the line along which light rays converge
(B) It is the axis perpendicular to the lens surface
(C) It is the line connecting the two focal points
(D) It indicates the boundary of the lens
Answer
Answer: (A) It is the line along which light rays converge
74. What kind of images can be formed by a concave lens?
(A) Real and inverted
(B) Virtual and erect
(C) Enlarged and real
(D) Diminished and real
Answer
Answer: (B) Virtual and erect
75. When an object is placed at the focus of a concave lens, where is the image formed?
(A) At the focus
(B) At infinity
(C) Virtual and on the same side as the object
(D) On the opposite side of the lens
Answer
Answer: (C) Virtual and on the same side as the object
76. What happens to light rays that pass through the optical center of a lens?
(A) They bend towards the normal
(B) They pass straight through without deviation
(C) They reflect back
(D) They converge at the focal point
Answer
Answer: (B) They pass straight through without deviation
77. How does the size of the image change as the object moves from the focal point towards a concave lens?
(A) The image size decreases
(B) The image size increases
(C) The image size remains the same
(D) The image disappears
Answer
Answer: (A) The image size decreases
78. If the object distance is greater than twice the focal length of a convex lens, what will be the nature of the image formed?
(A) Virtual and erect
(B) Real and inverted
(C) Diminished and virtual
(D) Enlarged and real
Answer
Answer: (B) Real and inverted
79. What is the characteristic of the image produced by a lens when the object is placed at its focal point?
(A) The image is virtual and enlarged
(B) The image is real and diminished
(C) The image is inverted and real
(D) The image is inverted and enlarged
Answer
Answer: (D) The image is inverted and enlarged
80. What does a negative value of the image distance indicate in lens optics?
(A) The image is real and inverted
(B) The image is virtual and erect
(C) The image is diminished
(D) The image is enlarged
Answer
Answer: (B) The image is virtual and erect
81. What is the formula for calculating the total power of multiple lenses in contact?
(A) P = P1 + P2 + P3 + …
(B) P = P1 * P2 * P3
(C) P = P1 – P2 – P3
(D) P = P1 / P2
Answer
Answer: (A) P = P1 + P2 + P3 + …
82. If a lens has a focal length of -20 cm, what type of lens is it?
(A) Concave lens
(B) Convex lens
(C) Cylindrical lens
(D) Biconvex lens
Answer
Answer: (A) Concave lens
83. When the object is located at the center of curvature of a concave mirror, the image formed is?
(A) Real and the same size
(B) Virtual and larger
(C) Real and smaller
(D) Virtual and the same size
Answer
Answer: (A) Real and the same size
84. In optical instruments, which lens is primarily used to magnify images?
(A) Concave lens
(B) Convex lens
(C) Plane lens
(D) Bifocal lens
Answer
Answer: (B) Convex lens
85. What happens to the image produced by a concave lens as the object distance decreases?
(A) It becomes larger
(B) It becomes smaller
(C) It remains the same size
(D) It moves closer to the lens
Answer
Answer: (B) It becomes smaller
86. What is the relationship between the magnification and the object distance in a lens?
(A) They are inversely proportional
(B) They are directly proportional
(C) They are equal
(D) They have no relationship
Answer
Answer: (A) They are inversely proportional
87. In a convex lens, if the object is moved closer to the focal point, what happens to the image?
(A) The image becomes real and inverted
(B) The image becomes virtual and erect
(C) The image size remains constant
(D) The image disappears
Answer
Answer: (B) The image becomes virtual and erect
88. Which of the following is a practical application of a concave lens?
(A) Used in magnifying glasses
(B) Used in rear-view mirrors
(C) Used in corrective glasses for myopia
(D) Used in projectors
Answer
Answer: (C) Used in corrective glasses for myopia
89. What effect does increasing the curvature of a lens have on its focal length?
(A) Focal length increases
(B) Focal length decreases
(C) Focal length remains the same
(D) Focal length becomes zero
Answer
Answer: (B) Focal length decreases
90. In which type of optical device is a biconvex lens commonly used?
(A) Diverging lens system
(B) Microscope
(C) Concave mirror
(D) Prism
Answer
Answer: (B) Microscope
91. What is the image type formed by a convex lens when the object is placed between F and 2F?
(A) Diminished and real
(B) Enlarged and real
(C) Virtual and erect
(D) Diminished and virtual
Answer
Answer: (B) Enlarged and real
92. What happens to the rays of light that are parallel to the principal axis after passing through a concave lens?
(A) They converge at the focal point
(B) They diverge as if coming from the focal point
(C) They continue in a straight line
(D) They reflect back
Answer
Answer: (B) They diverge as if coming from the focal point
93. If a concave lens has a focal length of -15 cm, what is its power?
(A) +6.67 D
(B) -6.67 D
(C) 0 D
(D) -15 D
Answer
Answer: (B) -6.67 D
94. What type of image does a concave lens produce regardless of the object’s position?
(A) Real and inverted
(B) Virtual and erect
(C) Enlarged and inverted
(D) Diminished and real
Answer
Answer: (B) Virtual and erect
95. What is the primary purpose of a convex lens in a camera?
(A) To focus light and form a real image
(B) To scatter light
(C) To create a virtual image
(D) To prevent light from entering
Answer
Answer: (A) To focus light and form a real image
96. In a lens formula, what does a negative value of the focal length indicate?
(A) The lens is convex
(B) The lens is concave
(C) The lens is a plane mirror
(D) The lens is not functioning
Answer
Answer: (B) The lens is concave
97. What is the main function of a lens in an optical instrument?
(A) To reflect light
(B) To absorb light
(C) To refract light and form images
(D) To produce sound
Answer
Answer: (C) To refract light and form images
98. When light travels from a medium with a lower refractive index to one with a higher refractive index, what happens?
(A) It bends away from the normal
(B) It bends towards the normal
(C) It reflects completely
(D) It remains unchanged
Answer
Answer: (B) It bends towards the normal
99. What type of image is formed by a convex lens when the object is placed closer than the focal length?
(A) Real and inverted
(B) Virtual and erect
(C) Diminished and real
(D) Enlarged and inverted
Answer
Answer: (B) Virtual and erect
100. Which type of lens is used to correct hyperopia (farsightedness)?
(A) Concave lens
(B) Convex lens
(C) Bifocal lens
(D) Cylindrical lens
Answer
Answer: (B) Convex lens
101. What is the relationship between the object distance (u), image distance (v), and focal length (f) in a lens?
(A) u + v = f
(B) 1/f = 1/v + 1/u
(C) f = u – v
(D) 1/v = 1/f – 1/u
Answer
Answer: (B) 1/f = 1/v + 1/u
102. How does increasing the power of a lens affect its focal length?
(A) Focal length increases
(B) Focal length decreases
(C) Focal length remains constant
(D) Focal length becomes negative
Answer
Answer: (B) Focal length decreases
103. Which of the following best describes the image produced by a concave lens?
(A) Real and enlarged
(B) Virtual and erect
(C) Real and inverted
(D) Diminished and inverted
Answer
Answer: (B) Virtual and erect
104. What is the effect of using a lens with a larger aperture?
(A) It decreases the amount of light entering
(B) It increases the amount of light entering
(C) It has no effect on light
(D) It distorts the image
Answer
Answer: (B) It increases the amount of light entering
105. What happens to light rays when they pass through a biconcave lens?
(A) They converge
(B) They diverge
(C) They reflect
(D) They refract towards the normal
Answer
Answer: (B) They diverge
106. In lens optics, what does a positive focal length indicate?
(A) The lens is concave
(B) The lens is convex
(C) The lens is a plane mirror
(D) The lens has no focal point
Answer
Answer: (B) The lens is convex
107. Which of the following statements is true about the image produced by a concave lens?
(A) It is always real
(B) It is always virtual and smaller
(C) It can be real or virtual
(D) It is always inverted
Answer
Answer: (B) It is always virtual and smaller
108. What is the relationship between the heights of the object and the image in a lens formula?
(A) h’ = h * (v/u)
(B) h’ = h + (v/u)
(C) h’ = h – (v/u)
(D) h’ = h * (u/v)
Answer
Answer: (A) h’ = h * (v/u)
109. How do you determine the total magnification when using multiple lenses?
(A) By multiplying the individual magnifications
(B) By adding the individual magnifications
(C) By subtracting the individual magnifications
(D) By averaging the individual magnifications
Answer
Answer: (A) By multiplying the individual magnifications
110. When light enters a medium with a higher refractive index, how does its speed change?
(A) Speed increases
(B) Speed decreases
(C) Speed remains the same
(D) Speed doubles
Answer
Answer: (B) Speed decreases
111. What type of image is produced when the object is placed at the focus of a convex lens?
(A) Real and inverted
(B) Virtual and erect
(C) Real and diminished
(D) Virtual and enlarged
Answer
Answer: (A) Real and inverted
112. What is the function of a corrective lens in eyeglasses?
(A) To focus light
(B) To scatter light
(C) To absorb light
(D) To reflect light
Answer
Answer: (A) To focus light
113. What is the primary characteristic of an image formed by a convex lens when the object is beyond 2F?
(A) Diminished and real
(B) Same size and real
(C) Enlarged and real
(D) Virtual and erect
Answer
Answer: (A) Diminished and real
114. In which case does a concave lens produce a virtual image?
(A) When the object is at infinity
(B) When the object is at the focus
(C) For all object distances
(D) When the object is beyond the focal length
Answer
Answer: (C) For all object distances
115. What does the focal point of a lens represent?
(A) The point where light rays diverge
(B) The point where parallel rays converge
(C) The center of the lens
(D) The optical center of the lens
Answer
Answer: (B) The point where parallel rays converge
116. Which of the following best describes the power of a lens?
(A) The ability to focus light
(B) The degree of light absorption
(C) The curvature of the lens
(D) The distance between the lens and the object
Answer
Answer: (A) The ability to focus light
117. If the image distance (v) is negative in the lens formula, what does this indicate?
(A) The image is virtual
(B) The image is real
(C) The lens is faulty
(D) The object is beyond focus
Answer
Answer: (A) The image is virtual
118. What happens to the focal length of a lens as its power increases?
(A) Focal length increases
(B) Focal length decreases
(C) Focal length remains the same
(D) Focal length becomes zero
Answer
Answer: (B) Focal length decreases
119. What is the purpose of using a lens in a magnifying glass?
(A) To reflect light
(B) To absorb light
(C) To enlarge the image of an object
(D) To scatter light
Answer
Answer: (C) To enlarge the image of an object
120. What is the sign convention for distances measured in the direction of incoming light?
(A) They are considered positive
(B) They are considered negative
(C) They are always zero
(D) They can be both positive and negative
Answer
Answer: (A) They are considered positive
121. What is the main difference between a concave and a convex lens in terms of image formation?
(A) Concave lenses can produce only real images
(B) Convex lenses can produce both real and virtual images
(C) Concave lenses always produce larger images
(D) Convex lenses are used only for correcting vision
Answer
Answer: (B) Convex lenses can produce both real and virtual images
122. In a simple optical system using lenses, what determines the total magnification?
(A) The shape of the lens
(B) The distance of the object
(C) The product of individual magnifications
(D) The focal length of the lens
Answer
Answer: (C) The product of individual magnifications
123. When light rays converge at a point after passing through a lens, what is that point called?
(A) Aperture
(B) Focus
(C) Vertex
(D) Principal axis
Answer
Answer: (B) Focus
124. If the object distance from a concave lens is decreased, what effect does it have on the image distance?
(A) It increases
(B) It decreases
(C) It remains unchanged
(D) It becomes infinite
Answer
Answer: (B) It decreases
125. What type of image does a convex lens produce when the object is placed at a distance less than the focal length?
(A) Real and inverted
(B) Virtual and erect
(C) Diminished and real
(D) Enlarged and real
Answer
Answer: (B) Virtual and erect
126. For a given lens, what happens to the power if the focal length is halved?
(A) Power decreases
(B) Power remains the same
(C) Power doubles
(D) Power becomes zero
Answer
Answer: (C) Power doubles
127. In the case of a lens, which of the following is true when the object is placed between the focal point and the lens?
(A) The image is real and inverted
(B) The image is virtual and enlarged
(C) The image is real and diminished
(D) The image is always at infinity
Answer
Answer: (B) The image is virtual and enlarged
128. What is the significance of the optical center of a lens?
(A) It is the point where light converges
(B) It is the point where light is absorbed
(C) Light passes through without deviation at this point
(D) It represents the focal length of the lens
Answer
Answer: (C) Light passes through without deviation at this point
129. What is the effect of using a biconcave lens in optical devices?
(A) To converge light rays
(B) To diverge light rays
(C) To reflect light
(D) To absorb light
Answer
Answer: (B) To diverge light rays
130. What is the nature of the image produced by a convex lens when the object is placed at 2F?
(A) Real and inverted, same size
(B) Virtual and erect, enlarged
(C) Real and inverted, enlarged
(D) Virtual and erect, same size
Answer
Answer: (A) Real and inverted, same size
131. Which of the following best describes the image formed by a biconvex lens when the object is placed beyond 2F?
(A) Virtual and enlarged
(B) Real and inverted
(C) Real and diminished
(D) Virtual and smaller
Answer
Answer: (B) Real and inverted
132. What happens to the image size as the object distance increases beyond 2F for a convex lens?
(A) The image size decreases
(B) The image size remains the same
(C) The image size increases
(D) The image disappears
Answer
Answer: (A) The image size decreases
133. If the focal length of a concave lens is -30 cm, what is its power?
(A) +3.33 D
(B) -3.33 D
(C) +30 D
(D) -30 D
Answer
Answer: (B) -3.33 D
134. What does the term ‘focal point’ refer to in optics?
(A) The distance from the lens to the object
(B) The point where light rays converge or appear to diverge
(C) The area where light is absorbed
(D) The width of the lens
Answer
Answer: (B) The point where light rays converge or appear to diverge
135. When using multiple lenses, how does one calculate the overall magnification?
(A) Add the individual magnifications
(B) Multiply the individual magnifications
(C) Subtract the individual magnifications
(D) Divide the individual magnifications
Answer
Answer: (B) Multiply the individual magnifications
136. Which type of lens is typically used in projectors to enlarge images?
(A) Concave lens
(B) Convex lens
(C) Bifocal lens
(D) Cylindrical lens
Answer
Answer: (B) Convex lens
137. What is the result of placing an object at a distance less than the focal length of a convex lens?
(A) A real and inverted image is formed
(B) A virtual and erect image is formed
(C) No image is formed
(D) An enlarged and diminished image is formed
Answer
Answer: (B) A virtual and erect image is formed
138. How does the focal length of a lens affect its power?
(A) Power is directly proportional to focal length
(B) Power is inversely proportional to focal length
(C) Power does not depend on focal length
(D) Power is equal to focal length
Answer
Answer: (B) Power is inversely proportional to focal length
139. When light passes from air into glass, what happens to its speed?
(A) It increases
(B) It decreases
(C) It remains constant
(D) It doubles
Answer
Answer: (B) It decreases
140. What happens to the rays of light passing through a lens when they meet at the focal point?
(A) They diverge
(B) They reflect
(C) They converge
(D) They scatter
Answer
Answer: (C) They converge
141. What is the significance of a lens’s principal focus in optics?
(A) It indicates the center of the lens
(B) It is where parallel rays converge or appear to diverge
(C) It marks the lens’s edge
(D) It is the point of maximum light absorption
Answer
Answer: (B) It is where parallel rays converge or appear to diverge
142. In a biconvex lens, which side is the focal point located on?
(A) On the same side as the object
(B) On the opposite side from the object
(C) It is located at the center of the lens
(D) It is irrelevant for image formation
Answer
Answer: (B) On the opposite side from the object
143. If an object is placed at the focus of a concave lens, what type of image will be produced?
(A) Real and enlarged
(B) Virtual and diminished
(C) Real and inverted
(D) Virtual and enlarged
Answer
Answer: (B) Virtual and diminished
144. What type of lens is used to correct nearsightedness (myopia)?
(A) Convex lens
(B) Concave lens
(C) Bifocal lens
(D) Cylindrical lens
Answer
Answer: (B) Concave lens
145. What happens when a light ray strikes the boundary between two media at an angle?
(A) It always reflects back
(B) It bends according to Snell’s Law
(C) It continues straight without any change
(D) It stops at the boundary
Answer
Answer: (B) It bends according to Snell’s Law
146. What is Snell’s Law used to determine?
(A) The speed of light in a vacuum
(B) The angle of incidence
(C) The angle of refraction
(D) The power of a lens
Answer
Answer: (C) The angle of refraction
147. If the refractive index of a medium is greater than 1, what does it indicate about the medium?
(A) It is less dense than air
(B) It is denser than air
(C) It reflects all light
(D) It absorbs all light
Answer
Answer: (B) It is denser than air
148. What is the term for the ratio of the speed of light in a vacuum to its speed in a medium?
(A) Optical density
(B) Refractive index
(C) Focal length
(D) Magnification
Answer
Answer: (B) Refractive index
149. When light travels from water to air, how does it behave?
(A) It bends towards the normal
(B) It bends away from the normal
(C) It travels straight
(D) It gets absorbed
Answer
Answer: (B) It bends away from the normal
150. What kind of image does a concave mirror produce when the object is located beyond the center of curvature?
(A) Virtual and erect
(B) Real and inverted
(C) Diminished and virtual
(D) Enlarged and real
Answer
Answer: (B) Real and inverted
151. In terms of light refraction, what is the effect of increasing the angle of incidence?
(A) The angle of refraction increases
(B) The angle of refraction decreases
(C) There is no effect
(D) The light reflects back
Answer
Answer: (A) The angle of refraction increases
152. What kind of optical instrument uses lenses to magnify distant objects?
(A) Telescope
(B) Microscope
(C) Projector
(D) Camera
Answer
Answer: (A) Telescope
153. What type of mirror is commonly used in vehicle headlights?
(A) Concave mirror
(B) Convex mirror
(C) Plane mirror
(D) Spherical mirror
Answer
Answer: (A) Concave mirror
154. What is the primary use of a convex mirror?
(A) To focus light
(B) To produce a real image
(C) To provide a wider field of view
(D) To magnify objects
Answer
Answer: (C) To provide a wider field of view
155. When an object is placed at the center of curvature of a concave mirror, the image formed is:
(A) Virtual and erect
(B) Real and the same size
(C) Diminished and real
(D) Enlarged and inverted
Answer
Answer: (B) Real and the same size
156. What happens to the nature of the image when the object is moved from beyond C to between F and C in a concave mirror?
(A) The image remains virtual
(B) The image becomes smaller
(C) The image becomes enlarged
(D) The image remains the same size
Answer
Answer: (C) The image becomes enlarged
157. Which of the following statements is true regarding the reflection of light?
(A) The angle of incidence is always less than the angle of reflection
(B) The angle of incidence equals the angle of reflection
(C) Light always reflects at a right angle
(D) The angle of incidence is greater than the angle of reflection
Answer
Answer: (B) The angle of incidence equals the angle of reflection
158. What is the image formed by a convex mirror when the object is placed at any distance?
(A) Real and inverted
(B) Virtual and erect
(C) Diminished and real
(D) Enlarged and real
Answer
Answer: (B) Virtual and erect
159. How does the distance of the object from a concave mirror affect the size of the image?
(A) Closer objects produce smaller images
(B) Closer objects produce larger images
(C) Distance has no effect on image size
(D) The image disappears when the object is too close
Answer
Answer: (B) Closer objects produce larger images
160. In optics, what is the principal focus of a concave mirror?
(A) The point where parallel rays converge
(B) The point where rays diverge
(C) The center of the mirror
(D) The point where light is absorbed
Answer
Answer: (A) The point where parallel rays converge
161. What phenomenon occurs when light rays are parallel to the principal axis after passing through a convex lens?
(A) They converge at the focal point
(B) They diverge
(C) They reflect back
(D) They scatter
Answer
Answer: (A) They converge at the focal point
162. In which optical device is a concave mirror typically used?
(A) Magnifying glass
(B) Telescope
(C) Searchlight
(D) Rear-view mirror
Answer
Answer: (C) Searchlight
163. When light enters a denser medium, how does its speed change?
(A) It increases
(B) It decreases
(C) It remains the same
(D) It stops
Answer
Answer: (B) It decreases
164. What type of mirror would you use to create a wide-angle view for safety while driving?
(A) Plane mirror
(B) Convex mirror
(C) Concave mirror
(D) Spherical mirror
Answer
Answer: (B) Convex mirror
165. What happens to the image distance (v) when an object is moved further away from a concave mirror?
(A) It increases
(B) It decreases
(C) It remains unchanged
(D) It becomes negative
Answer
Answer: (A) It increases
166. What is the relationship between the angle of incidence and the angle of reflection?
(A) They are equal
(B) Angle of incidence is always greater
(C) Angle of incidence is always less
(D) They have no relationship
Answer
Answer: (A) They are equal
167. In a convex lens, what happens to the image when the object is located between the focal point and the lens?
(A) The image is real and inverted
(B) The image is virtual and enlarged
(C) The image is diminished and real
(D) The image is always at infinity
Answer
Answer: (B) The image is virtual and enlarged
168. What type of image does a concave mirror form when the object is between the mirror and the focal point?
(A) Real and diminished
(B) Virtual and erect
(C) Real and inverted
(D) Virtual and inverted
Answer
Answer: (B) Virtual and erect
169. What is the term used to describe the bending of light as it passes from one medium to another?
(A) Reflection
(B) Refraction
(C) Diffraction
(D) Absorption
Answer
Answer: (B) Refraction
170. In which situation does total internal reflection occur?
(A) When light travels from a denser medium to a rarer medium at an angle greater than the critical angle
(B) When light travels from a rarer medium to a denser medium
(C) When light strikes a mirror
(D) When light passes through a transparent medium
Answer
Answer: (A) When light travels from a denser medium to a rarer medium at an angle greater than the critical angle
171. What is the critical angle in optics?
(A) The angle at which light reflects back into a medium
(B) The angle at which light refracts
(C) The angle of incidence that results in no refraction
(D) The maximum angle at which total internal reflection can occur
Answer
Answer: (A) The angle at which light reflects back into a medium
172. Which optical phenomenon explains the twinkling of stars?
(A) Reflection
(B) Refraction
(C) Diffraction
(D) Dispersion
Answer
Answer: (B) Refraction
173. What is the effect of increasing the angle of incidence on the angle of refraction in a denser medium?
(A) The angle of refraction decreases
(B) The angle of refraction increases
(C) The angle of refraction remains constant
(D) There is no effect
Answer
Answer: (B) The angle of refraction increases
174. In optical fibers, what principle allows light to be transmitted through the fiber?
(A) Reflection
(B) Refraction
(C) Total internal reflection
(D) Diffraction
Answer
Answer: (C) Total internal reflection
175. What is the primary reason that lenses are used in microscopes?
(A) To scatter light
(B) To absorb light
(C) To magnify images
(D) To reflect light
Answer
Answer: (C) To magnify images
176. How does the refractive index change as the density of a medium increases?
(A) It decreases
(B) It increases
(C) It remains the same
(D) It fluctuates
Answer
Answer: (B) It increases
177. What happens to light rays when they pass through a converging lens?
(A) They diverge
(B) They converge to a point
(C) They scatter
(D) They reflect back
Answer
Answer: (B) They converge to a point
178. Which optical device uses the principle of refraction to magnify small objects?
(A) Telescope
(B) Magnifying glass
(C) Projector
(D) Camera
Answer
Answer: (B) Magnifying glass
179. What is the characteristic of the image formed by a biconcave lens?
(A) Virtual and enlarged
(B) Real and inverted
(C) Virtual and diminished
(D) Real and diminished
Answer
Answer: (C) Virtual and diminished
180. When an object is placed at infinity, where is the image formed by a convex lens?
(A) At the focal point
(B) At the center of curvature
(C) At infinity
(D) Between the lens and focus
Answer
Answer: (A) At the focal point
181. In optics, what does the term ‘aperture’ refer to?
(A) The distance between the lens and the object
(B) The width of the lens
(C) The diameter of the lens opening
(D) The focal length of the lens
Answer
Answer: (C) The diameter of the lens opening
182. What type of image is produced by a convex mirror?
(A) Real and inverted
(B) Virtual and erect
(C) Diminished and real
(D) Enlarged and real
Answer
Answer: (B) Virtual and erect
183. What is the significance of the lens’s optical center?
(A) It is where light converges
(B) It is where light passes without deviation
(C) It is the edge of the lens
(D) It indicates the focal length
Answer
Answer: (B) It is where light passes without deviation
184. How does the distance of an object from a concave mirror affect the size of the image?
(A) Closer objects produce smaller images
(B) Closer objects produce larger images
(C) Distance has no effect on image size
(D) The image disappears when the object is too close
Answer
Answer: (B) Closer objects produce larger images
185. What type of lens is used to correct myopia (nearsightedness)?
(A) Convex lens
(B) Concave lens
(C) Bifocal lens
(D) Cylindrical lens
Answer
Answer: (B) Concave lens
186. What is the main principle behind the working of a lens?
(A) Reflection of light
(B) Absorption of light
(C) Refraction of light
(D) Diffraction of light
Answer
Answer: (C) Refraction of light
187. Which of the following statements is true about the images formed by concave mirrors?
(A) They are always virtual
(B) They can be both real and virtual
(C) They are always diminished
(D) They are always enlarged
Answer
Answer: (B) They can be both real and virtual
188. When light enters a medium with a lower refractive index, what happens to its speed?
(A) It decreases
(B) It increases
(C) It remains the same
(D) It stops
Answer
Answer: (B) It increases
189. What happens when light strikes a surface at the critical angle?
(A) It reflects back into the medium
(B) It refracts at 90 degrees
(C) It continues in a straight line
(D) It stops
Answer
Answer: (A) It reflects back into the medium
190. What is the effect of increasing the curvature of a lens on its focal length?
(A) Focal length increases
(B) Focal length decreases
(C) Focal length remains the same
(D) Focal length becomes zero
Answer
Answer: (B) Focal length decreases
191. In a converging lens, what type of image is produced when the object is placed between the focal point and the lens?
(A) Real and inverted
(B) Virtual and erect
(C) Real and enlarged
(D) Virtual and diminished
Answer
Answer: (B) Virtual and erect
192. What is the role of the diaphragm in a camera?
(A) To focus light
(B) To control the amount of light entering
(C) To reflect light
(D) To absorb light
Answer
Answer: (B) To control the amount of light entering
193. What happens when light passes from air to water?
(A) It bends away from the normal
(B) It bends towards the normal
(C) It reflects back
(D) It travels straight
Answer
Answer: (B) It bends towards the normal
194. Which law describes the relationship between the angles of incidence and refraction?
(A) Law of Reflection
(B) Snell’s Law
(C) Law of Refraction
(D) Law of Dispersion
Answer
Answer: (B) Snell’s Law
195. In a glass prism, what phenomenon occurs when white light passes through it?
(A) Reflection
(B) Refraction
(C) Dispersion
(D) Absorption
Answer
Answer: (C) Dispersion
196. What type of image is formed when the object is placed at the focus of a convex lens?
(A) Real and diminished
(B) Virtual and erect
(C) Real and inverted
(D) Virtual and enlarged
Answer
Answer: (B) Virtual and erect
197. What is the purpose of a plano-convex lens?
(A) To diverge light
(B) To focus light
(C) To reflect light
(D) To create shadows
Answer
Answer: (B) To focus light
198. How does a concave mirror affect parallel rays of light?
(A) They diverge
(B) They converge at the focal point
(C) They continue straight
(D) They reflect back
Answer
Answer: (B) They converge at the focal point
199. What is the refractive index of air considered to be?
(A) 1.33
(B) 1.00
(C) 1.5
(D) 2.00
Answer
Answer: (B) 1.00
200. Which optical instrument uses lenses to produce magnified images of small objects?
(A) Telescope
(B) Microscope
(C) Projector
(D) Camera
Answer
Answer: (B) Microscope
201. What is the primary function of a diverging lens?
(A) To focus light rays
(B) To spread light rays apart
(C) To invert images
(D) To magnify images
Answer
Answer: (B) To spread light rays apart
202. When light travels from a medium with a higher refractive index to one with a lower refractive index, what happens?
(A) It bends towards the normal
(B) It bends away from the normal
(C) It reflects completely
(D) It remains unchanged
Answer
Answer: (B) It bends away from the normal
203. What is the term for the angle of incidence that results in total internal reflection?
(A) Critical angle
(B) Refraction angle
(C) Angle of deviation
(D) Angle of reflection
Answer
Answer: (A) Critical angle
204. In optics, what does ‘dispersion’ refer to?
(A) The spreading of light into its component colors
(B) The bending of light at an interface
(C) The reflection of light from surfaces
(D) The absorption of light by materials
Answer
Answer: (A) The spreading of light into its component colors
205. Which type of lens is thicker at the center than at the edges?
(A) Concave lens
(B) Convex lens
(C) Bifocal lens
(D) Plano-convex lens
Answer
Answer: (B) Convex lens
206. What is the result when a beam of white light passes through a prism?
(A) It reflects
(B) It bends
(C) It disperses into a spectrum of colors
(D) It does not change
Answer
Answer: (C) It disperses into a spectrum of colors
207. How do concave mirrors form images?
(A) Only real images
(B) Only virtual images
(C) Both real and virtual images depending on the object’s position
(D) No images at all
Answer
Answer: (C) Both real and virtual images depending on the object’s position
208. What type of image does a convex mirror always produce?
(A) Real and inverted
(B) Virtual and erect
(C) Diminished and real
(D) Enlarged and real
Answer
Answer: (B) Virtual and erect
209. What type of lens is typically used in a projector to enlarge images?
(A) Concave lens
(B) Convex lens
(C) Bifocal lens
(D) Cylindrical lens
Answer
Answer: (B) Convex lens
210. What occurs during total internal reflection?
(A) Light is absorbed by the medium
(B) Light bends away from the normal
(C) Light reflects back into the medium
(D) Light passes through the medium
Answer
Answer: (C) Light reflects back into the medium
211. What is the critical angle for total internal reflection dependent on?
(A) The speed of light in vacuum
(B) The refractive index of the two media
(C) The angle of incidence
(D) The color of the light
Answer
Answer: (B) The refractive index of the two media
212. What is the effect of increasing the thickness of a lens on its focal length?
(A) Focal length increases
(B) Focal length decreases
(C) Focal length remains unchanged
(D) Focal length becomes infinite
Answer
Answer: (B) Focal length decreases
213. In a camera, what is the purpose of the aperture?
(A) To focus light
(B) To control the amount of light entering
(C) To magnify the image
(D) To reflect light
Answer
Answer: (B) To control the amount of light entering
214. How does a diverging lens affect parallel rays of light?
(A) They converge
(B) They remain parallel
(C) They diverge as if coming from the focal point
(D) They reflect back
Answer
Answer: (C) They diverge as if coming from the focal point
215. What happens to the image when the object is placed at the focal point of a convex lens?
(A) The image is real and diminished
(B) The image is virtual and erect
(C) The image is real and inverted
(D) The image is at infinity
Answer
Answer: (D) The image is at infinity
216. What is the characteristic of light rays passing through the optical center of a lens?
(A) They bend towards the normal
(B) They bend away from the normal
(C) They pass through without deviation
(D) They reflect off the lens
Answer
Answer: (C) They pass through without deviation