Electrical force on a point unit charge which is at a distance x, exerted by a point charge q = electric field =
the direction of electric field is along the line joining the charges.
variation of electric field with distance from the point charge =
The electric potential at point P (at distance x from origin) due to the electric point charge q at the origin = V
V = energy required to move a unit charge q₀ from infinity, against the electric force due to charge q, to the point P at a distance x away from q.
the variation of electric potential with distance is