Question

Derive an expression for the intensity of the electric field at a point on the axial line of an electric dipole. point on the axial line of an electric dipole.

Answer 1

Electric field at a point on the axis of a dipole :

(1) Consider an electric dipole consisting of two charges –q and +q separated by a distance '2a' with centre 'O'.

(2) We shall calculate electric field E at point P on the axial line of dipole, and at a distance OP = r.

(3) Let E₁ and E₂ be the intensities of electric field at P due to charges +q and –q respectively.