According to Benjamin Franklin, we have two types of electric charges i.e. positive and negative charges. Positive and negative charges attract, but positive charges repel each other, as do negative charges.
The force F that a pair of electric charges Q1 and Q2, separated by a distance r, exert on one another is given by the following equation:
where k is a constant.
The above equation is known as Coulomb’s law named after the French physicist Charles Augustin de Coulomb. The Qs in the equation represent some number of coulombs (The unit of charge is also named after Coulomb).
Coulomb’s law states that any electric charge exerts a force on other charges in the vicinity. We can think of the charge as creating a field called the electric field.
Related: Uses of Static Electricity
