What happens if one of the slits, say S1 in Young’s double, slit experiment-is covered with a glass plate which absorbs half the intensity of light from it?
(a) The bright fringes become less-bright and the dark fringes have a finite light intensity.
(b) The bright fringes become brighter and the dark fringes become darker.
(c) The fringe width decreases.
(d) No fringes will be observed.
What is the reason for your answer to the above question?
(a) The two sources do not emit light of the same wavelength.
(b) The two sources emit waves which travel with different speeds.
(c) The two sources emit light waves of different amplitudes.
(d) There is not constant phase difference between the waves emitted by the two sources.
Two sources of light are said to be coherent when both give out light waves of the same:
(a) amplitude and phase.
(b) intensity and wavelength.
(c) speed.
(d) wavelength and a constant phase difference.
Which of the following is conserved when light waves interference?
(a) phase.
(b) intensity.
(c) amplitude.
(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.
Which among the following isn’t a suitable phenomenon to establish that light is wave motion?
a) Interference.
b) Diffraction.
c) Reflection.
d) Polarization.
The locus of all particles in a medium, vibrating in the same phase is called
(a) wavelet.
(b) fringe.
(c) wave front.
(d) None of these.
Wavefront is the locus of all points, where the particles of the medium vibrate with the same
(a) phase.
(b) amplitude.
(c) frequency.
(d) period.
When light suffers reflection at the interface between water and glass, the change of phase in the reflected wave is
(a) zero..
(b) π.
(c) π/2.
(d) 2π.
Two sources of light are said to be coherent, when they give light waves of same
(a) amplitude and phase.
(b) wavelength and constant phase difference.
(c) intensity and wavelength.
(d) phase and speed.
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.
Unpolarized light is incident on a plane glass surface The angle of incidence so that reflected and refracted rays are perpendicular to each other, them
(a) tan iβ= μ/2
(b) tan iβ = μ
(c) sin iβ = μ
(d) cos iβ = μ
To observe diffraction, the size of the obstacle
(a) should be X/2, where X is the wavelength.
(b) should be of the order of wavelength.
(c) has no relation to wavelength.
(d) should be much larger than the wavelength.
In Young’s double-slit experiment, the phase difference between the light waves reaching the third bright fringe from the central fringe will be (λ=6000 Å)
(a) zero
(b)2
(c) 4
(d) 6