Question

The dipole moment of a molecule is 10⁻³⁰ Cm. It is placed in an electric field E⃗ of 10⁵ V/m such that its axis is along the electric field. The direction of E⃗ is suddenly changed by 60° at an instant. Find the change in the potential energy of the dipole, at that instant.

Dipoles, whether electric or magnetic, are characterised by their dipole moments, which are vector quantities. Two equal and opposite charges separated by a small distance constitute an electric dipole, while a current carrying loop behaves as a magnetic dipole. Electric dipoles create electric fields around them. Electric dipoles experience a torque when placed in an external electric field.

Two identical electric dipoles are placed along the diagonals of a square ABCD of side √2 m as shown in the figure. Obtain the magnitude and direction of the net electric field at the centre (O) of the square.

An electric dipole of length 2 cm is placed at an angle of 30° with an electric field 2 × 10⁵ N/C. If the dipole experiences a torque of 8 × 10⁻³ Nm, the magnitude of either charge of the dipole, is