The electric potential V at any point (x1, y1, z1) in space is given by V = 4x2 volt. The electric field at (1, 0, 2) m in Vm-1 is
8, along negative x-axis
8, along positive x-axis
16, along negative x-axis
16, along positive y-axis
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
zero
A capacitor of capacitance 2 μF is charged to a potential difference of 200 volts. After disconnecting from the battery, it is connected in parallel with another uncharged capacitor. The common potential is 40 volts. The capacitance of the second capacitor is
2 μF
4 μF
8 μF
16 μF
A capacitor connected to a 10 V battery collects a charge of 40 μC with air as dielectric, and 100 μC with oil as dielectric. The dielectric constant of oil is
4
8
2.5
1.5
Capacitance (in F) of a spherical conductor with radius 1 m is
1.1 × 10-10
10-6
9 × 10-6
10-3
Two equally charged small balls A and B, placed at a fixed distance experience a force F. A similar uncharged ball C after touching one of them is placed at a middle point between the two balls. The force experienced by ball A, is
2F
4F
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 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
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
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
