You turn an electric dipole end for end in a uniform electric field.How does the work you do depend on the initial orientation of the dipole with respect to the field?

Answer 1

The work done by you to turn the electric dipole end for end in a uniform electric field depends on the initial orientation of the dipole with respect to the field. If the dipole is initially oriented such that its positive and negative charges are parallel to the electric field, then no net work is done as the electric field does not do any work on the dipole as the electric field lines do not transfer any energy. On the other hand, if the dipole is initially oriented such that its positive and negative charges are perpendicular to the electric field, then work is done by you to turn the dipole as the electric field exerts a force on the charges in the dipole in opposite directions, causing them to move in opposite directions. As a result, you have to do work to move the charges and turn the dipole.

Answer 2

The work done depends on the angle between the initial orientation of the dipole and the electric field. If the initial orientation is aligned with the electric field, no work is done in turning the dipole. If the initial orientation is perpendicular to the electric field, the maximum work is done. The work done is proportional to the magnitude of the electric field, the dipole moment, and the cosine of the angle between them.