Question

Derive an expression for the torque acting on a dipole in a uniform electric field.​

Answer 1

Let the force of qE is applied in the electric field on each charge of the dipole. A couple rotate the dipole during to the equal and opposite force on the points of action. The torque(T) of the dipole is (qE×2dsinθ where d is the length of the dipole and θ is angle between the dipole and the direction of the field.