A 4 μF conductor is charged to 400 V and then its plates are joined through a resistance of 1 kΩ. The heat produced in the resistance is
0.16 J
1.28 J
0.64 J
0.32 J
Two spherical conductors A and B of radii 1 mm and 2 mm are separated by a distance of 5 cm and are uniformly charged. If the spheres are connected by a conducting wire then in equilibrium condition, the ratio of the magnitude of the electric fields at the surfaces of spheres A and B is
4 :1
1 : 2
2 : 1
1 : 4
A particle of mass m and charge q is placed at rest in a uniform electric field E and then released. The Kinetic energy attained by the particle after moving a distance y is
q E y2
q E2 y
q E y
q2 E y
The formation of a dipole is due to two equal and dissimilar point charges placed at a
short distance
long distance
above each other
none of the above
The dielectric strength of air at NTP is 3 × 106 V/m. The maximum charge that can be given to a spherical conductor of radius 3 m is
3 × 104 C
3 × 10-3 C
3 × 10-2 C
3 × 10-1 C
A hollow insulated conducting sphere is given a positive charge of 10μC. What will be the electric field at the centre of the sphere if its radius is 2 m?
zero
5 μCm-2
20 μCm-2
8 μCm-2
If the potential of a capacitor having capacity 6μF is increased from 10V to 20 V, then increase in its energy will be
4 x 10-4 J
4 x 10-14 J
9 x 10-4 J
12 x 10-6 J
The study of the effects associated with electric charges at rest is called
electromagnetism
electrostatics
magnetostatics
none of these
Electric potential of earth is taken to be zero because earth is a good
dielectric
semiconductor
insulator
conductor
Some charge is being given to a conductor, then its potential is
maximum at surface
maximum at centre
same throughout the conductor
maximum somewhere between surface and centre