Electrostatics ...

A parallel plate capacitor of capacitance 100 pF is to be constructed by using paper sheets of 1.0 mm thickness as dielectric. If the dielectric constant of paper is 4.0, the number of circular metal foils of diameter 2.0 cm each required for this purpose is

In a hydrogen atom, the electron and the proton are bound together at a separation of about 0.53 Å. If the zero of potential energy is taken for an infinite separation of the electron from the proton, then the potential energy of the electron-proton system is

Electric charges are of

n identical capacitors are joined in parallel and the combination is charged to voltage V. The total energy stored is U. The capacitors are now disconnected and joined in series. The total energy stored in the series combination will be

A soap bubble of radius r is charged to a potential V. If the radius is increased to nr, the potential of the bubble will become

Electric charge