Electrostatics ...

Conservation of charges in tribo electric charging 

Four metal plates numbered 1, 2, 3 and 4 are arranged as shown in the figure. The area of each plate is A and the separation between adjacent plates is d. The capacitance of the arrangement is

Two positive point charges of 12 and 8 microcoulombs are placed 10 cm apart in air. The work done to bring them 4 cm closer is

The effective capacitance of two capacitors of capacitances C₁ and C₂ (with C₂ > C₁) connected in parallel is  times the effective capacitance when they are connected in series. The ratio of C₂ and C₁ is

A parallel plate capacitor of plate area A and plate separation d is charged by a battery of voltage V. The work needed to pull the plates to a separation 2d, when the battery is disconnected, is

If 10⁹ electrons move out of a body to another body every second, how much time is approximately required to get a total charge of 1 C on the other body?

The force of attraction between the plates of an air-filled parallel plate capacitor having charge Q and area of each plate A is given by

Which of the following methods can be used to charge a metal sphere positively without touching it . Select the best

Which of the following statements is true for the circuit shown in the figure?

The potential difference between points A and B in the given circuit is

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 . 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

Four capacitors, each of capacitance 50 F, are connected as shown in the figure. If the voltmeter reads 100 V, the charge on each capacitor is

Three capacitors, each of capacitance C = 3 , are connected as shown in the figure. The equivalent capacitance between points P and S 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

What is the equivalent capacitance between A and D in the figure given below?

A cube of side b has a charge q at each of its vertices. What is the electric potential at the centre of the cube?

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