Light-Reflection and Refraction class 10th Important MCQ

 

Light-Reflection and Refraction class 10th Important MCQ

PART A: REFLECTION OF LIGHT (1–50)

Plane Mirror (1–10)

1. The image formed by a plane mirror is
   A) real and inverted
   B) virtual and erect
   C) real and erect
   D) virtual and inverted
   Ans: B
2. Magnification of a plane mirror is
   A) –1
   B) +1
   C) 0
   D) >1
   Ans: B
3. Distance between object and image in plane mirror when object is 2 m away is
   A) 2 m
   B) 3 m
   C) 4 m
   D) 1 m
   Ans: C
4. If the mirror is moved by 1 cm, image moves by
   A) 0.5 cm
   B) 1 cm
   C) 2 cm
   D) 4 cm
   Ans: C
5. Image formed by plane mirror is laterally inverted because
   A) reflection
   B) refraction
   C) rotation
   D) translation
   Ans: A
6. The size of image in plane mirror is
   A) smaller
   B) larger
   C) same as object
   D) zero
   Ans: C
7. Which mirror is used as looking mirror?
   A) concave
   B) convex
   C) plane
   D) parabolic
   Ans: C
8. Image distance in plane mirror is
   A) less than object distance
   B) equal to object distance
   C) double object distance
   D) zero
   Ans: B
9. Nature of image in plane mirror is
   A) real
   B) virtual
   C) inverted
   D) diminished
   Ans: B
10. Lateral inversion is seen in
    A) convex mirror
    B) concave mirror
    C) plane mirror
    D) lens
    Ans: C

Spherical Mirrors (11–30)

11. Focal length of a concave mirror is taken as
    A) positive
    B) negative
    C) zero
    D) infinite
    Ans: B
12. Which mirror always forms a virtual image?
    A) concave
    B) plane
    C) convex
    D) parabolic
    Ans: C
13. Image formed by convex mirror is always
    A) real and inverted
    B) virtual and erect
    C) real and erect
    D) virtual and inverted
    Ans: B
14. Object at focus of concave mirror forms image at
    A) focus
    B) centre
    C) infinity
    D) pole
    Ans: C
15. Radius of curvature is related to focal length by
    A) R = f
    B) R = 2f
    C) f = R/4
    D) f = R
    Ans: B
16. Object between F and P of concave mirror forms image
    A) real, inverted
    B) virtual, erect
    C) real, erect
    D) virtual, inverted
    Ans: B
17. Image formed at centre of curvature of concave mirror is
    A) diminished
    B) enlarged
    C) same size
    D) virtual
    Ans: C
18. Convex mirror is used as rear-view mirror because
    A) magnified image
    B) real image
    C) wider field of view
    D) inverted image
    Ans: C
19. Image distance is positive for
    A) real image
    B) virtual image
    C) inverted image
    D) diminished image
    Ans: B
20. Magnification is negative when image is
    A) erect
    B) virtual
    C) real and inverted
    D) diminished
    Ans: C
21. Mirror formula is
    A) 1/f = 1/v – 1/u
    B) 1/f = 1/v + 1/u
    C) f = u + v
    D) v = u + f
    Ans: B
22. Unit of focal length is
    A) cm
    B) dioptre
    C) meter
    D) both A and C
    Ans: D
23. Image formed by concave mirror can be
    A) only real
    B) only virtual
    C) real or virtual
    D) none
    Ans: C
24. Convex mirror has
    A) negative f
    B) positive f
    C) zero f
    D) infinite f
    Ans: B
25. Object at infinity in concave mirror forms image at
    A) pole
    B) focus
    C) centre
    D) infinity
    Ans: B
26. Image is highly enlarged and virtual when object is
    A) at C
    B) beyond C
    C) at F
    D) between F and P
    Ans: D
27. Which mirror can produce real image?
    A) convex
    B) plane
    C) concave
    D) all
    Ans: C
28. Magnification formula for mirror is
    A) m = u/v
    B) m = v/u
    C) m = f/u
    D) m = f/v
    Ans: B
29. If m = –1, image is
    A) virtual
    B) erect
    C) same size
    D) diminished
    Ans: C
30. Image distance is negative when image is
    A) virtual
    B) real
    C) erect
    D) magnified
    Ans: B

PART B: REFRACTION OF LIGHT (31–100)

Basic Refraction & Refractive Index (31–50)

31. Refraction occurs due to change in
    A) wavelength
    B) speed
    C) frequency
    D) direction only
    Ans: B
32. Speed of light is maximum in
    A) glass
    B) water
    C) vacuum
    D) diamond
    Ans: C
33. Refractive index is defined as
    A) sin r / sin i
    B) sin i / sin r
    C) v / c
    D) c / v
    Ans: D
34. Unit of refractive index is
    A) m
    B) m/s
    C) none
    D) dioptre
    Ans: C
35. Bending of light towards normal occurs when light travels from
    A) denser to rarer
    B) rarer to denser
    C) vacuum to vacuum
    D) none
    Ans: B
36. Frequency of light changes on refraction
    A) yes
    B) no
    Ans: B
37. Which law relates angles of incidence and refraction?
    A) reflection law
    B) Newton law
    C) Snell’s law
    D) Huygens law
    Ans: C
38. Refractive index of vacuum is
    A) 0
    B) 1
    C) 1.33
    D) ∞
    Ans: B
39. Optical density depends on
    A) mass density
    B) refractive index
    C) thickness
    D) color
    Ans: B
40. When light goes from glass to air, it bends
    A) towards normal
    B) away from normal
    C) no bending
    D) totally reflected
    Ans: B
41. Relative refractive index is ratio of
    A) wavelengths
    B) speeds
    C) frequencies
    D) amplitudes
    Ans: B
42. Angle of emergence in glass slab is
    A) greater than i
    B) less than i
    C) equal to i
    D) zero
    Ans: C
43. Lateral displacement depends on
    A) slab thickness
    B) angle of incidence
    C) refractive index
    D) all
    Ans: D
44. In glass slab, emergent ray is
    A) perpendicular
    B) parallel
    C) opposite
    D) curved
    Ans: B
45. Refractive index increases when speed
    A) increases
    B) decreases
    C) constant
    D) zero
    Ans: B

Lenses & Power of Lens (46–100)

46. Convex lens is also called
    A) diverging
    B) converging
    C) plane
    D) concave
    Ans: B
47. Concave lens always forms image
    A) real
    B) virtual
    C) inverted
    D) magnified
    Ans: B
48. Sign of focal length of convex lens is
    A) negative
    B) positive
    C) zero
    D) infinity
    Ans: B
49. Lens formula is
    A) 1/f = 1/v + 1/u
    B) 1/f = 1/v – 1/u
    C) f = u + v
    D) v = u – f
    Ans: A
50. Power of lens is measured in
    A) meter
    B) cm
    C) dioptre
    D) watt
    Ans: C
51. Power of convex lens is
    A) negative
    B) zero
    C) positive
    D) infinite
    Ans: C
52. Power of concave lens is
    A) positive
    B) negative
    C) zero
    D) infinite
    Ans: B
53. Focal length and power relation is
    A) P = f
    B) P = 1/f
    C) P = f²
    D) P = 1/f²
    Ans: B
54. Unit of focal length in power formula is
    A) cm
    B) mm
    C) meter
    D) km
    Ans: C
55. Lens forming image at infinity has object at
    A) focus
    B) centre
    C) infinity
    D) pole
    Ans: A
56. Magnification of lens is
    A) v/u
    B) u/v
    C) f/v
    D) f/u
    Ans: A
57. If m is positive, image is
    A) real
    B) inverted
    C) virtual and erect
    D) diminished
    Ans: C
58. Concave lens focal length is
    A) +ve
    B) –ve
    C) zero
    D) ∞
    Ans: B
59. Convex lens can form
    A) only real
    B) only virtual
    C) both real & virtual
    D) none
    Ans: C
60. Net power of two lenses in contact is
    A) product
    B) difference
    C) sum
    D) ratio
    Ans: C

PART C: LENSES, SIGN CONVENTION & NUMERICAL MCQs (61–100)

Lens & Image Formation (61–80)

61. A convex lens forms a real and inverted image when the object is placed
    A) between O and F
    B) at F
    C) beyond F
    D) at O
    Ans: C
62. A concave lens always forms an image which is
    A) real and inverted
    B) real and erect
    C) virtual and erect
    D) virtual and inverted
    Ans: C
63. The focal length of a lens is measured from
    A) focus to focus
    B) centre of curvature
    C) optical centre
    D) pole
    Ans: C
64. For a convex lens, focal length is taken as
    A) negative
    B) positive
    C) zero
    D) infinite
    Ans: B
65. An object placed at 2F of a convex lens forms image at
    A) F
    B) infinity
    C) 2F
    D) O
    Ans: C
66. Image formed by a convex lens when object is within focal length is
    A) real, inverted
    B) virtual, erect
    C) real, erect
    D) virtual, inverted
    Ans: B
67. If u = –20 cm and v = +40 cm, magnification is
    A) –2
    B) +2
    C) –0.5
    D) +0.5
    Ans: B
68. A lens has power +4 D. Its focal length is
    A) 25 m
    B) 0.25 m
    C) –0.25 m
    D) –4 m
    Ans: B
69. Which lens has negative power?
    A) convex
    B) plane
    C) concave
    D) cylindrical
    Ans: C
70. Image distance is positive for a lens when image is
    A) real
    B) inverted
    C) virtual
    D) diminished
    Ans: A
71. A lens with large focal length has
    A) large power
    B) small power
    C) zero power
    D) infinite power
    Ans: B
72. A convex lens of small focal length is
    A) weak lens
    B) no lens
    C) powerful lens
    D) plane lens
    Ans: C
73. The SI unit of power of lens is
    A) metre
    B) watt
    C) dioptre
    D) joule
    Ans: C
74. If the power of lens is zero, focal length is
    A) zero
    B) one
    C) infinite
    D) negative
    Ans: C
75. A real image formed by a lens is always
    A) erect
    B) virtual
    C) inverted
    D) diminished
    Ans: C
76. Image size depends on
    A) focal length only
    B) object distance only
    C) magnification
    D) refractive index
    Ans: C
77. If magnification is –1, the image is
    A) erect and same size
    B) inverted and same size
    C) inverted and diminished
    D) erect and enlarged
    Ans: B
78. A lens used to correct myopia is
    A) convex
    B) concave
    C) cylindrical
    D) plane
    Ans: B
79. A lens used to correct hypermetropia is
    A) concave
    B) plane
    C) convex
    D) prism
    Ans: C
80. When two lenses are in contact, net power is
    A) difference of powers
    B) product of powers
    C) sum of powers
    D) ratio of powers
    Ans: C

Mixed Concept MCQs (81–100)

81. Light changes its speed when it enters a new medium due to
    A) reflection
    B) dispersion
    C) refraction
    D) scattering
    Ans: C
82. Refractive index of a medium depends on
    A) speed of light
    B) wavelength
    C) nature of medium
    D) all
    Ans: D
83. The bending of light is maximum when it passes from
    A) glass to air
    B) air to glass
    C) water to air
    D) vacuum to air
    Ans: B
84. Which quantity remains constant during refraction?
    A) speed
    B) wavelength
    C) frequency
    D) direction
    Ans: C
85. If μ increases, speed of light
    A) increases
    B) decreases
    C) remains same
    D) becomes zero
    Ans: B
86. Angle of refraction is smaller than angle of incidence when light travels from
    A) rarer to denser
    B) denser to rarer
    C) air to air
    D) vacuum to vacuum
    Ans: A
87. A glass slab causes lateral displacement because
    A) emergent ray is bent
    B) opposite faces are parallel
    C) slab is thick
    D) refractive index is low
    Ans: B
88. The image formed by concave mirror can be virtual when object is
    A) beyond C
    B) at C
    C) at F
    D) between P and F
    Ans: D
89. Which mirror has positive focal length?
    A) concave
    B) plane
    C) convex
    D) parabolic
    Ans: C
90. A convex mirror always gives image which is
    A) real
    B) inverted
    C) enlarged
    D) virtual
    Ans: D
91. A ray passing through centre of curvature retraces its path in
    A) lens
    B) prism
    C) mirror
    D) slab
    Ans: C
92. The unit of radius of curvature is
    A) dioptre
    B) metre
    C) watt
    D) joule
    Ans: B
93. A lens forms image at infinity when object is placed at
    A) focus
    B) centre
    C) optical centre
    D) infinity
    Ans: A
94. Convex lens is thick at
    A) edges
    B) centre
    C) both
    D) nowhere
    Ans: B
95. Concave lens is thick at
    A) centre
    B) edges
    C) pole
    D) focus
    Ans: B
96. The optical centre of a lens is a point where
    A) image forms
    B) light bends
    C) ray passes undeviated
    D) reflection occurs
    Ans: C
97. Magnification of concave lens is always
    A) negative
    B) zero
    C) positive and <1
    D) >1
    Ans: C
98. If f = –20 cm, the lens is
    A) convex
    B) plane
    C) concave
    D) cylindrical
    Ans: C
99. A real image can be obtained on a screen by
    A) concave lens
    B) convex lens
    C) plane mirror
    D) convex mirror
    Ans: B
100. Power of a lens depends on
     A) object distance
     B) image distance
     C) focal length
     D) thickness only
     Ans: C

 Read also : Light-Reflection and Refraction Part-1 class 10 Full chapter Notes with Solved Numericals.

Read also : Light-Reflection and Refraction Part-2 class 10 Full chapter Notes with Solved Numericals.

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