Two currents loops are concentric and lie in the same plane. The current in the outer loop is anti clockwise and increasing with time. The induced current in the inner loop ,is
(a) Clockwise
(b) Zero
(c) Counter-clockwise
(d) None of these
Two point charges, \(q_1\) = 10 × \(10^{-8}\)C, \(q_2\) = -2 × \(10^{-8}\)C are seperated by a distance of 60 cm in air what is the electrostatic potential energy of the system.
1) 3 joule
2) -3 joule
3) -3 x\(10^{-5}\) joule
4) 3 x\(10^{-5}\) joule
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.
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
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.
What is the SI unit of electric potential?
(a) J/C
(b) J-C
(c) v-m
(d) J/c-m
When 2 × \(10^{11}\) electrons are removed from a neutral metal sphere, the charge on the sphere becomes:
(A) -16 nC
(B) 16 nC
(C) -32 nC
(D) 32nC
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.
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.
Which of the following phenomenon is not explained by Huygen’s wave theory?
(a) Diffraction
(b) Polarisation
(c) Photoelectric effect
(d) Interference
Which of the following statements indicates that light waves are transverse?
(a) Light waves can be polarised
(b) Light waves can show interference
(c) Light waves undergo diffraction
(d) They travel in the vacuum
A Young’s double – slit set up for interference is shifted from air to within water. Then the
(A) Fringe pattern disappear
(B) fringe width decreases
(C) fringe width increases
(D) fringe width remains unchanged
In double –slit experiment the distance of the second dark fringe from the central line is 3 mm. The distance of the fourth bright fringe from the central line is
(A) 6 mm
(B) 8mm
(C) 12 mm
(D) 16 mm
In Young’s experiment with one source and two slits, one of the slits is covered with black paper. Then
(A) The fringes will be darker
(B) The fringes will be narrower
(C) The fringes will be broader
(D) No fringes will be obtained and the screen will have uniform illumination
To obtain a sustained interference pattern we require two sources which emit radiation of
(A) the same frequency
(B) nearly same frequency
(C) the same frequency having a definite phase relationship
(D) different wavelengths