Question

what is Dipole in a uniform external field?

Answer 1

Consider a permanent dipole of dipole moment 'p' in a uniform external field E, which implies that p does not depend E nor it is induced due to E.

The force on q is qE and on -q is -qE and net force on dipole is zero. However, the charges are separated so the force act on different points, giving rise to a torque (twisting force) on the dipole. When net force is zero, torque is independent of the origin. Its magnitude equals the magnitude of each force multiplied by perpendicular distance between the two antiparallel forces. That is,

Magnitude of torque (t) = qE x 2a sinq

In vector notationare assumed to be in the plane of the paper.

From the above, it is found that an electric dipole placed in uniform electric field experiences a torque which align the dipole parallel to the direction of the electric field

Answer 2

Explanation:

Dipole in a uniform electric field. Dipole in a uniform electric field. When two charges in a dipole are separated by some distance, the forces acting at different points result in torque on the dipole.