Question

derive expression for potential energy of an electric dipole placed in uniform electric field.

Answer 1

Explanation:

the potential energy is maximum when the electric dipole is alinged antibparallel

Answer 2

Consider an electric dipole of dipole moment placed at an angle 0 in the direction of a uniform electric field.

The dipole experiences torque,

τ = P x E = pE sinθ

This torque tends to rotate the dipole in the direction of the electric field.

The work done in rotating the dipole from a position of0 potential energy  to any given position in the field then,

$W=pE[cos\frac{\pi }{2}-cos o]$

Potential energy= U

Therefore, the potential energy of an electric dipole in a uniform Electric field is,

U = -pE cosθ