Coulomb’s law
The electrostatic force between two point charges is proportional to the product of their charges and inversely proportional to the square of the distance between them.
Electric field strength
The Electric field strength at a point in a field is the force which is exerted on a unit positive charge placed in the field
Electric Potential
The electric potential at any point in an electric field is the work done in bringing a unit positive charge from infinity to that point