On moving a charge of 20 coluomb by 2 cm, 2 J of work is done, then the potential difference between the points is
0.1 V
8 V
2 V
0.5 V
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
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 cylinder of radius R and length L is placed in a uniform electric field E parallel to the axis of the cylinder. The total flux from the surface of cylinder is given by
2pR2E
Zero
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
The four capacitors, each of 25 μF are connected as shown in figure. The DC voltmeter reads 200 V. The charge on one each plate of capacitor is
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
A 4μF 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
A pendulum bob of mass 30.7 x 10-6 kg and carrying a charge 2 x 10-8 C is at rest in a horizontal uniform electric field of 20000 V/m. The tension in the thread of the pendulum is (g = 9.8 m/s2).
3 x 104 N
4 x 10-4 N
5 x 10-4 N
6 x 10-4 N
In bringing an electron towards another electron, the electrostatic potential energy of the system
decreases
increases
remains same
becomes zero
