The electric field is defined as the electric force on the test charge per unit charge. The electric field vector, , at a point in space is defined as the electric forceacting on a positive point-like test charge, qo, placed at that point divided by the test.

The electric field vector is a mathematical description of the magnitude and the direction of the electric field. How to find out the Electric Field vector at a point on a equipotential surface. The electric field is given by the negative gradient of the potential. →E=−→∇V.