Question

An electric dipole of moment `p` is placed in the positive of stable equilibrium in uniform electric field of intensity `E`. It is rotated through an angle `theta` from the initial position. The potential energy of electric dipole in the final position is
A. `pE cos theta`
B. `pE sin theta`
C. `pE (1 - cos theta)`
D. `-pE cos theta`

Answer 1

Correct Answer - D
Potential energy of dipole in electric field `U = - pE cos theta`, where `theta` is the angle between electric field and dipole.