Question

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.

Depict the orientation of an electric dipole in (a) stable and (b) unstable equilibrium in an external uniform electric field. Write the potential energy of the dipole in each case.

(i) Derive an expression for potential energy of an electric dipole p in an external uniform electric field E. When is the potential energy of the dipole (1) maximum, and (2) minimum ? (ii) An electric dipole consists of point charges − 1·0 pC and + 1·0 pC located at (0, 0) and (3 mm, 4 mm) respectively in x − y plane. An electric field E = (1000 V/m)î is switched on in the region. Find the torque acting on the dipole.

An electric dipole of dipole moment 2 × 10⁻⁸ C-m in a uniform electric field experiences a maximum torque of 6 × 10⁻⁴ N-m. The magnitude of electric field is