High School Physics

# Electric potential – definition, formula, sample numerical

Last updated on May 11th, 2022 at 09:48 am

In this post, we will discuss the following: (1) definition of electric potential, (2) formula of electric potential, (3) solving a sample numerical problem using the formula of electric potential.

## Definition of electric potential

The electric potential at a point in an electric field is defined as the work done in bringing a unit positive charge from infinity to that point (units: volts).

An alternative definition: The electric potential at a point is the potential energy of a unit positive charge placed at that point with the zero being at infinity.

## formula of electric potential

The electric potential (V ) at a point, at a distance r from a charge Q, is given by the equation:
V = [1/(4πε0)][Q/r]

## formula of electric potential energy from the formula of electric potential

If a charge q is placed in an electric field, its electric potential energy is qV.

The electric potential energy at a point in a radial field = qV = [1/(4πε0)][qQ/r]

## sample numerical problem

Calculate the electric potential at a distance of 0.5 m from a charge of 0.5 mC.

Solution: