Coulomb’s law, or Coulomb’s inverse-square law, is a law of physics describing the electrostatic interaction between electrically charged particles. Coulomb’s law states that : “The magnitude of the electrostatic force of interaction between two point charges is directly proportional to the scalar multiplication of the magnitudes of charges and inversely proportional to the square of the distance between them.”
The force is along the straight line joining them. If the two charges have the same sign, the electrostatic force between them is repulsive; if they have different sign, the force between them is attractive.
|F||Coulomb force (N)|
|q1||signed magnitude of charge q1 (coulombs)|
|q2||signed magnitude of charge q2 (coulombs)|
|r||distance between the charges (m)|