A dipole of moment 0.5 e·nm is placed in a uniform electric field with a magnitude of 4.0 x 104 N/C. What is the magnitude of the torque on the dipole when
(a) The dipole is parallel to the electric field,
(b) The dipole is perpendicular to the electric field, and
(c) The dipole makes an angle of 30o with the electric field?
(d) Find the potential energy of the dipole in the electric field for each case.