MCQs of Waves Optics

Waves Optics MCQs

MCQs of Waves Optics

Showing 71 to 80 out of 131 Questions

71.

Unpolarized light falls on two polarizers placed one on top the other. What must be the angle between characteristic directions (optic axis) of the polarizer if the intensity of the transmitted light is one third of the incident beam ?

(a)	54.7°
(b)	35.3°
(c)	0°
(d)	60°

72.

Which of the following can not be explained by formation wavefront by Huygen's theory ?

(a)	Refraction
(b)	Reflection
(c)	Diffraction
(d)	Sources of spectrum

73.

Huygen's principle for secondary waves is _____

(a)	used to find focal length of lens.
(b)	a method to find wavefront using geometry
(c)	used to find velocity of light
(d)	used to explain polarisation

74.

Interference is possible only for ____ type of waves.

(a)	longitudinal
(b)	transverse
(c)	mechanical
(d)	all

75.

Resultant amplitude of super position of wave shown by

\vec{e_{1}} = \vec{E_{1}} \sin δ_{1} and \vec{e_{2}} = \vec{E_{2}} {sinδ}_{2} is

_____

(a)	$\sqrt{{E_{1}}^{2} + {E_{2}}^{2} + 2 E_{1} E_{2} \cos (δ_{2} - δ_{1})}$
(b)	$\sqrt{{E_{1}}^{2} + {E_{2}}^{2} + 2 E_{1} E_{2} s i n (δ_{2} + δ_{1})}$
(c)	$E_{1} + E_{2}$
(d)	$E_{1} - E_{2}$

76.

In Young's experiment, the distance between two slits is kept of the order _____

(a)	0.1 m
(b)	0.1 cm
(c)	0.01 cm
(d)	0.01 m

77.

In Young's experiment two Coherent sources are obtained by _____

(a)	two independent light sources
(b)	two light division
(c)	division of wavefront
(d)	division of amplitude

78.

Light takes time t to cover distance d in air so distance covered by it in time t from medium having refractive index μ will be _____

(a)	$\frac{μ}{d}$
(b)	$μ d$
(c)	$\frac{d}{μ}$
(d)	$μ t$

79.

A glass plate of thickness d and refractive index n is placed on the path of one of the two coming out of two slits in Young's experiment. The minimum thickness of plate for having zero intensity of central bright fringe should be _____ λ is the wavelength of light.

(a)	$(n - 1) \frac{λ}{2}$
(b)	$\frac{λ}{n - 1}$
(c)	$\frac{λ}{2 (n - 1)}$
(d)	$(n - 1) λ$

80.

Two electromagnetic waves create (0, 0, 1) Vm^-1 and (-1, 0, 1) Vm^-1 displacement at one point at any instance. So resultant intensity at this point will be _____Wm^-2

(a)	$\sqrt{5}$
(b)	17
(c)	1
(d)	5

Showing 71 to 80 out of 131 Questions