An electric dipole moment `p` is placed in an electric field of intensity `'E'`. The dipole acquires a position such that the axis of the dipole makes an angle `theta` with the direction of the field. Assuming that the potential energy of the dipole to be zero when `theta= 90^(@)`, the torque and the potential energy of the dipole will respectively be

Options

A. `pE sin theta, -p E cos theta`
B. `pE sin theta, -2p E cos theta`
C. `pE sin theta, 2p E cos theta`
D. `pE cos theta, -pE sin theta`

Answer

A

Explanation

Torque, `tau = pE sin theta`
Potential energy, `U = - p E cos theta`