Question

An electric dipole is held in a uniform electric field
(i) show that net force acting on it is zero
(ii) Find the torque acting on a dipole and specify its direction.
(iii) If the dipole is aligned parallel to the field. Find the work done in rotating through angle of 180°.

Answer 1

1) The forces experienced by the 2
charges constituting the electric dipole
when placed in an uniform external
electric field are equal and opposite in
nature, the net force on the dipole is
zero.

2) Angle of rotation-180
than

Torque-pE sin180 = 0

No torque act on the dipole when the
moment of electric dipole is parallel to
the electric field.