The electric potential due to point charge 3 nC at distance of 9 cm is
(a) 270 v
(b) 3 v
(c) 300 v
(d) 30 v
(a) 270 v
(b) 3 v
(c) 300 v
(d) 30 v
(c) 300 v
The electrostatic potential energy between proton and electron separated by a distance of 1 Å is
(a) 13.6eV
(b) 27.2eV
(c) -14.4eV
(d) 1.44eV
The capacitance of earth, viewed as a spherical conductor of radius 6408 km is:
(a) 1420 μF
(b) 712 μF
(c) 680 μF
(d) 540 μF
Electric potential at a distance r from the point charge is proportional to
1. \(r^2\)
2. r-1
3. r0
4. r+1
Why are electric field lines perpendicular at a point on an equipotential surface of a conductor ?
Minimum number of capacitor of 2μF each required to obtain a capacitance of 5μF will be:
(a) 4
(b) 3
(c) 5
(d) 6
In Young’s double slit experiment, the two slits are separated by 1 mm and the screen is placed at 1 m away. It produces the second dark fringe at At a distance of 2mm from the central fringe, the wavelength of monochromatic light used would be
(A) 1.3 x \(10^{-6}\) m
(B) 2 x \(10^{-6}\) cm
(C) 2 x \(10^{-9}\) m
(D) 1.3 x \(10^{-6}\) cm
Twenty-seven drops of mercury are charged simultaneously to the same potential of 10 volts. What will be potential if all the charged drops are made to combine to form one large drop ?
(a) 180 V
(b) 90 V
(c) 120 V
(d) 45 V
In an interference experiment, the spacing between successive maxima and minima is
(A) λd / D
(B) λD / d
(C) dD / λ
(D) λd / 4D
Which of the following is conserved when light waves interference?
(a) phase.
(b) intensity.
(c) amplitude.
(d) none of these.
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 monochromatic light waves of amplitudes 3A and 2A interfering at a point having phase difference of \(60^\circ\). The intensity of light at that point will be
(A) 5\(A^2\)
(B) 13\(A^2\)
(C) 7\(A^2\)
(D) 19\(A^2\)
Huygens wave theory allows us to know
A) The wavelength of the wave
(B) The velocity of the wave
(C) The amplitude of the wave
(D) The propagation of wave-fronts