A 100 μF capacitor is charged to a potential difference of 50 V, the charging battery then being disconnected. The capacitor is then connected to a second capacitor. If the measured potential difference drops to 35 V, the capacitance of the second capacitor is
52 μF
37 μF
59 μF
43 μF
The electric field required to just support a water droplet of mass 10-5 g, which has a charge of 10-13 C is
107 V m-1
9.8 × 103 V m-1
106 V m-1
9.8 × 105 V m-1
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
The potential of a point A is -500 V and that of another point B is +500 V. The work done by an external agent to take 2 units of negative charge from B to A is
+1000 J
-1000 J
+2000 J
-2000 J
Electric potential of earth is taken to be zero because earth is a good
dielectric
semiconductor
insulator
conductor
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
There is an electric field E in x - direction. If the work done on moving a charge of 0.2 C through a distance of 2 m along a line making an angle 60o with x-axis is 4 J, then what is the value of E?
3 N/C
4 N/C
5 N/C
20 N/C
A point charge + q is placed at midpoint of a cube of side L. The electric flux emerging from the cube is
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 work done in carrying a charge Q once round the circle of radius r with charge Q at the centre of the circle is
