Coulomb Law

State Coulomb’s inverse-square law in electrostatics.

The electrostatic force of attraction or repulsion between two stationary point charges is directly proportional to the product of the magnitudes of the charges and inversely proportional to the square of the distance between them.

What are the limitations of Coulomb’s law?

Coulomb’s law holds good for stationary point charges.
Coulomb’s law is not universal, as it depends on the properties of the intervening medium.

Is the electrostatic force between two point charges a central force?

Yes. The electrostatic force between two point charges always acts along the line joining the two charges. Hence, it is a central force.

What is one Coulomb of charge?

One Coulomb of charge is that charge which, when placed at rest in a vacuum at a distance of one metrer from an equal and similar stationary charge, repels it and is repelled by it with a force of 9 x 10⁹ Newton.