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 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
Two equally charged small balls A and B, placed at a fixed distance experience a force F. A smilar 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
