When a polaroid is rotated, the intensity of light varies but never reduces to zero. It shows that theincident light is:
a. Unpolarised
b. completely plane polarised
c. partially plane polarised
d. one of the above
a. Unpolarised
b. completely plane polarised
c. partially plane polarised
d. one of the above
c. partially plane polarised
When ordinary light is made incident on a quarter wave plate, the emergent light is
(a) linearly polarised.
(b) circularly polarised.
(c) unpolarised.
(d) elliptically polarised.
An optically active compound
(a) rotates the plane of polarised light
(b) changes the direction of polarised light
(c) does not allow plane polarised light to pass through
(d) none of these
An optically active compound
(a) rotates the plane of polarised light.
(b) changes the direction of polarised light.
(c) does not allow plane polarised light to pass through.
(d) none of these.
Polaroid glasses is used in sun glasses because :
a. It reduces the light intensity to half on account of polarization
b. It is fashionable
c. It has good colour
d. It is cheaper
In interference pattern, the energy is
A) created at maximum
(B) destroyed at minimum
(C) conserves but re-disturbed
(D) none of the above
For sustained interference, we need two sources which emit radiations:
(a) of the same intensity
(b) of the same amplitude
(c) having a constant phase difference
(d) None of these
Which of the following is conserved when light waves interfere?
(a) phase
(b) intensity
(c) amplitude
(d) none of these
In young’s double slit experiment slits are separated by 0.32mm, and screen is at 1.6m away. Then find out the least distance from the central bright fringe where the bright fringes of wavelengths as 800nm and 600nm are coinciding.
(A) 10mm
(B) 12mm
(C) 1.2mm
(D) 1.0mm
In Young’s double slit experiment, using sodium light (λ = 5898) , 92 fringes are seen. If given colour (λ= 5461) is used, how many fringes will be seen?
I. 67
II. 95
III. 99
IV. 84
Which of the following phenomenon is not explained by Huygen’s wave theory?
(a) Diffraction
(b) Polarisation
(c) Photoelectric effect
(d) Interference
In a circuit with a coil of resistance 3Ω, the magnetic flux changes from 1.0 Wb to 10.0 Wb in 0.3 s. The charge that flows in the coil during this time is
(a) 2.0 C
(b) 3.0 C
(c) 4.0 C
(d) 1.0 C
The fringe width (β) of a diffraction pattern and the slit width d are related as:
(a) β ∝ d
(b) β ∝1/d
(c) β ∝ √d
(d) β ∝ 1/\(d^2\)
In a purely resistive a.c. circuit, the current
(a) is in phase with the e.m.f.
(b) leads the e.m.f. by a difference of π radians phase
(c) leads the e.m.f. by a phase difference of π/2 radians
(d) lags behind the e.m.f. by a phase difference of π/4 radians
A diffraction pattern is obtained by using a beam of red light. What will happen if the red light is replaced by the blue light.
a. No change will take place.
b. Bands become broader and farther apart.
c. Bands disappear
d. Diffraction bands become narrower and crowded.