MCQs of Waves Optics

Waves Optics MCQs

MCQs of Waves Optics

Showing 61 to 70 out of 131 Questions

61.

In Young's experiment if transparent thin sheets are placed in front of two thin slits such that the central bright fringe remain at the same position. Thickness and refractive index of both sheet are

t_{1} and t_{2} and n_{1} and n_{2} respectively . In this case,

_____

(a)	$\frac{t_{1}}{t_{2}} = \frac{n_{1}}{n_{2}}$
(b)	$\frac{t_{2}}{t_{1}} = \frac{n_{2}}{n_{1}}$
(c)	$\frac{t_{1}}{t_{2}} = \frac{(n_{2} - 1)}{(n_{1} - 1)}$
(d)	$\frac{t_{2}}{t_{1}} = \frac{(n_{2} - 1)}{(n_{1} - 1)}$

62.

A plate of thickness λ and refractive index 1.5 is placed in the passage of one ray in Young's experiment. If the central fringe is bright, the minimum thickness of the plate is _____

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

63.

Intensity of two sources are different and waves emitting from source experience interference. If ratio of maximum and minimum intensity in interference is 25, intensity of sources is _____

(a)	5 : 1
(b)	9 : 4
(c)	25 : 16
(d)	25 : 1

64.

The angular spread of central maximum, in diffraction pattern, does not depends on _____

(a)	the distance between the slit and sources
(b)	wavelength of light
(c)	width of silt
(d)	frequency of light

65.

Which of the following can not be polarised ?

(a)	Ultrasonic waves
(b)	Ultraviolet rays
(c)	Radio waves
(d)	X-rays.

66.

Detailed information can be obtained by the oil immersion objective of a microscope, because the objective has _____

(a)	large value of magnification.
(b)	greater value of resolution.
(c)	large diameter.
(d)	none of the above.

67.

A person finds that the sun rays reflected by the still surface of water in a lake are polarized. If the refractive index of water is 1.327, the sun will be seen at an angle of _____ with the horizon.

(a)	57°
(b)	75°
(c)	37°
(d)	53°

68.

Ordinary light incident on a glass slab, at the polarizing angle, suffers a deviation of 22°. The value of angle of refraction is _____

(a)	74°
(b)	22°
(c)	90°
(d)	34°

69.

The ratio of resolving power of telescope, when light of wavelength 4000 Å and 5000 Å are used, is _____

(a)	16 :25
(b)	5 : 4
(c)	4 : 5
(d)	9 : 1

70.

The diameter of lens of a telescope is 1.22 m. The wavelength of light is 5000 Å. The resolving power of the telescope is _____m^-1.

(a)	2 × 10⁵
(b)	2 × 10⁶
(c)	2 × 10²
(d)	2 × 10⁴

Showing 61 to 70 out of 131 Questions