**The electric potential energy** of an electric dipole in an electrostatic field is the work done in rotating the dipole to the desired position in the field.

When an electric dipole of dipole moment p is at an angle θ with the electric field E, the torque on the dipole is

**τ = pE sin θ**

Work done in rotating the dipole through dθ,

**dw = τ.dθ = pE sinθ.dθ**

The total work done in rotating the dipole through an angle θ is **W = ∫dw**

**W = pE ∫sinθ.dθ = –pE cos θ**

This work done is the potential energy (U) of the dipole.

so, **U = – pE cos θ**

When the dipole is aligned parallel to the field, θ = 0^{0}

so, **U = –pE**

This shows that the dipole has a minimum potential energy when it is aligned with the field. A dipole in the electric field experiences a torque **(τ = p * E)** which tends to align the dipole in the field direction, dissipating its potential energy in the form of heat to the surroundings.