Question

In vector form, how is the torque on a dipole expressed in terms of dipole moment and electric field?

Options

• \[\tau = \mathbf{p} \cdot \mathbf{E}\]

• \[\tau = \mathbf{E}/\mathbf{p}\]

• \[\tau = \mathbf{p} \times \mathbf{E}\]

• \[\tau = \mathbf{p} + \mathbf{E}\]

Answer 1

The vector form of torque is expressed as the cross product of dipole moment and electric field: \[\tau = \mathbf{p} \times \mathbf{E}\]. The magnitude of this cross product gives pE sin θ, where θ is the angle between the vectors, and the direction follows the right-hand rule.