Torque on an electric dipole in a uniform electric field:

Let us consider two charges ‘+q’ and ‘-q’ which are separated from each other with a distance ‘2a’ are placed in a uniform electric field E.

Dipole moment in given as,

p = q x 2a.

Force exerted on charge ‘+q’ by an electric field, F = qE.

Force exerted on charge ‘-q’ by an electric field, F = -qE.

Net Force = +qE – qE = 0.

P = Electric dipole moment = q x 2a

E = Electric field intensity.

τ = Torque.