Ray Optics & Optical Instruments  MCQs

MCQs of Ray Optics & Optical Instruments

Showing 51 to 60 out of 143 Questions
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51.
The frequency of incident light is 3 x 1018 Hz. The frequency after reflection _____ .
(a) decreases
(b) increases
(c) remains same
(d) None of the above
Answer:

Option (c)

52.
A ray is incident at an angle of 38° with a mirror. The angle between normal and reflected ray is _____ .
(a) 52°
(b) 38°
(c) 90°
(d) 70°
Answer:

Option (a)

53.
Bhautik runs towards a plane mirror with a speed of 15 ms-1. What is the speed of his image with respect to mirror ?
(a) 7.5 ms-1
(b) 15 ms-1
(c) 38 ms-1
(d) 45 ms-1
Answer:

Option (b)

54.
To get three images of a single object, one should have two plane mirrors at an angle of _____ .
(a) 60°
(b) 120°
(c) 180°
(d) 90°
Answer:

Option (d)

55.
A magnification of a plane mirror is _____ .
(a) 0
(b) -1
(c) +1
(d) ∞
Answer:

Option (c)

56.
If a glass rod is immersed in a liquid of the same refractive index as that of glass, then it will _____ .
(a) disappear
(b) look bent
(c) look longer
(d) look shorter
Answer:

Option (a)

57.
When the light rays enter into a glass slab, their wavelength _____ .
(a) increases
(b) decreases
(c) remains constant
(d) None of these
Answer:

Option (b)

58.
Green light of wavelength 5460 A∘ is incident on an air and glass interface. If refractive index of glass is 1.5, then wavelength of light in glass would be _____ .
(a) 5460 A∘
(b) 4860 A∘
(c) 3640 A∘
(d) 2100 A∘
Answer:

Option (c)

59.
For five different transparent medium, n54 x n43 x n32 x n21 = _____ .
(a) 1n15
(b) n15
(c) 1n51
(d) None of these
Answer:

Option (a)

60.
Optical fibres are based on _____ .
(a) refraction
(b) total internal reflection
(c) scattering
(d) None of the above
Answer:

Option (b)

Showing 51 to 60 out of 143 Questions
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