Coulomb’s Law

Force of interaction (attraction or repulsion) between two static point charges is called electrostatic forces. For two static point charges electrostatic forces is described by Coulomb’s law

is called electrostatic constant. The quantity e_o is called permitivity of free space (vacuum /air). Its value is e_o = 8.98755 x 10 ^–12 N^{– 1} m ^{– 2} C ²

Dimensions of permittivity: [M ^{– 1} A² L^{– 3} T⁴ ]

Charge which exerts force is called source & which experiences it is called victim.