Force between two point charges (interaction force) is directly proportional to the product of magnitude of charges ( and ) and is inversely proportional to the square of the distance between them i.e., . This force is conservative in nature. This law is also called inverse square law. The direction of force is always along the line joining the point charges.
Coulomb’s Law in Vector Form
Suppose the position vectors of two charges and are and , then, electric force on charge due to charge is,
Similarly, electric force on due to charge is
Here and are to be substituted with sign. Position vector of charges and are and respectively where and are the coordinates of charges and .