10 QUESTIONS AND ANSWERS ABOUT ELECTROSTATICS.

What principle is used to calculate the forces of more than two charges?

The superposition principle explains the interaction between multiple charges.

What is an electric dipole?

Two equal and opposite charges separated by a small distance constitute an electric dipole.

Write an example of an electric dipole?

In many molecules, the centres of positive and negative charge do not coincide. Such molecules behave as permanent dipoles. Like CO, H₂O, HCl.

What is the charge of the proton?

 The charge of proton is +1.6×10^-19 C

What is the charge of an electron?

 The charge of a proton and the charge of an electron both are the same but different in sign. The charge of an electron is -1.6×10^-19 C

Which law is correct to compare with Coulomb’s law?

 Coulomb’s law has the same structure as Newton’s law of gravitation.

What is the electric dipole moment and SI unit of dipole moment?

The magnitude of the electric dipole moment is equal to the product of the magnitude of one of the charges and the distance between them. The SI unit of dipole moment is coulomb meter (Cm)

P = 2qa

Calculate the number of electrons in one coulomb of negative

Charge.

The quantization of charge q = ne, q = 1C.

 n = q/e = 1C/1.6×10^-19 = 6.25×10¹⁸ electrons.

What is the relative permittivity of water?

The relative permittivity of water is Ԑ_r = 80.

The electric field lines start from which charge?

The electric field lines start with a positive charge and end at a negative charge.