Waves Optics  MCQs

MCQs of Waves Optics

Showing 11 to 20 out of 131 Questions
11.
In Fraunhoffer diffraction by a single slit, the width of the slit is 0.01 cm. If the wavelength of light incident normally on the slit is 6000 Å the angular distance of second maximum from the mid line of central maximum is _____ rad.
(a) 0.015
(b) 0.15
(c) 0.075
(d) 0.030
Answer:

Option (a)

12.
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 the angle of _____ with the horizon.
(a) 57°
(b) 75°
(c) 37°
(d) 53°
Answer:

Option (c)

13.
Ordinary light incident on a glass slab, at the polarizing angle, suffers a deviation of 22°. in the medium. The value of angle of refraction is _____ .
(a) 74°
(b) 22°
(c) 90°
(d) 34°
Answer:

Option (d)

14.
The ratio of resolving power of telescope , when lights of wavelength 4000 Å and 5000 Å are used, is _____.
(a) 16 : 25
(b) 5 : 4
(c) 4 : 5
(d) 9 : 1
Answer:

Option (b)

15.
The diameter of the 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
Answer:

Option (b)

16.
Unpolarized light falls on two polarizers placed one on top the other. What must be the angle between the characteristic directions (optic axis) of the polarizer if the intensity of the transmitted light is one third of the incident beam from source.
(a) 54.7°
(b) 35.3°
(c)
(d) 60°
Answer:

Option (b)

17.
If A is the amplitude of a wave coming from a point source at a distance r then _____
(a) A r
(b) A r-1
(c) A r2
(d) A r12
Answer:

Option (b)

18.
The ray of light _____
(a) is always normal to wavefront
(b) is always tangential to wavefront
(c) does not exist in the Huygen's principle
(d) may be tangential or normal to wavefront
Answer:

Option (a)

19.
Wave optics is valid, when the dimensions of object are _____
(a) of the order of one micrometer
(b) of the same order as wavelength of light
(c) much larger than that the wavelength of light
(d) much smaller than that the wavelength of light
Answer:

Option (b)

20.
In Hygen's wave theory, the locus of all points oscillating in teh same phase is called a _____
(a) ray
(b) vibrator
(c) wavefront
(d) half period zone
Answer:

Option (c)

Showing 11 to 20 out of 131 Questions