MCQs of Ray Optics & Optical Instruments

Ray Optics & Optical Instruments MCQs

MCQs of Ray Optics & Optical Instruments

Showing 81 to 90 out of 143 Questions

81.

Light is incident on a glass plate at an incident angle of 60°. If reflected and refracted rays are mutually perpendicular, then refractrive index of the glass plate is _____ .

(a)	$\sqrt{2}$
(b)	$\sqrt{3}$
(c)	$\frac{1}{\sqrt{2}}$
(d)	$\frac{1}{\sqrt{3}}$

82.

A ray of light strikes a glass plate at an incident angle Θ. If angle between the reflected and refracted rays is right angle, then refractive index of glass plate is given by _____ .

(a)	μ = sin Θ
(b)	μ = cos Θ
(c)	μ = tan Θ
(d)	μ = cot Θ

83.

A sound wave travels from air to water. The angle of incidence is α₁ and the angle of refraction is α₂. If the snell's law is valid, then _____ .

(a)	α₁ = α₂
(b)	α₁ > α₂
(c)	α₁ < α₂
(d)	None of these

84.

A ray of light passes from glass (μ = 1.5) to water (μ = 1.33). The value of the critical angle of glass is _____ .

(a)	$\sin^{- 1} (\frac{8}{9})$
(b)	$\sin^{- 1} (\sqrt{\frac{8}{9}})$
(c)	$\sin^{- 1} (\frac{1}{2})$
(d)	$\sin^{- 1} (\frac{2}{1})$

85.

If the critical angle for total internal reflection from a medium to vacuum is 30°, then the velocity of light in the medium is _____ ms^-1. (c = 3 x 10⁸ ms^-1)

(a)	3.0 x 10⁸
(b)	2.0 x 10⁸
(c)	1.5 x 10⁸
(d)	10⁸

86.

A double convex lens is manufactured from a glass of refractive index 1.55 with both faces of same radii of curvature. If focal length of lens is 20 cm, their radius of curvature will be _____ cm.

(a)	22
(b)	44
(c)	66
(d)	88

87.

A plano-convex lens is made of refractive index 1.6. The radius of curvature of the curved surface is 60 cm. The focal length of the lens is _____ cm.

(a)	50
(b)	100
(c)	-50
(d)	-100

88.

In a plano-covex lens, the radius of curvature of the convex surface is 10 cm. If focal length of the lens is 30 cm, then refractive index of the lens is _____ cm.

(a)	1.1
(b)	1.22
(c)	1.33
(d)	1.66

89.

If the refractive index of a material of an equilateral prism is

\sqrt{3}

, then angle of minimum deviation will be _____ .

(a)	30°
(b)	40°
(c)	50°
(d)	60°

90.

A thin prism of 4° angle made from glass of refractive index 1.54 is combined with another thin prism made from glass of refractive index 1.72 to produce dispersion without deviation. What is the angle of second prism ?

(a)	-3°
(b)	4°
(c)	5°
(d)	-6°

Showing 81 to 90 out of 143 Questions