13.4 COULOMB'S LAW
We know that a force of attraction or repulsion acts between two charged bodies. How is this force affected when the magnitude of the charge on the two bodies or the distance between them is changed? In order to find the answers of these questions, a French scientist Charles Coulomb (1736- 1806) in 1785 experimentally established the fundamental law of electric force between two stationary charged particles.
Coulomb's Law: The force of attraction or repulsion between two point charges is directly proportional to the product of the magnitude of charges and inversely proportional to the square of the distance between them.