An electric dipole with dipole moment 4 × 10⁻⁹ C m is aligned at 30° with the direction of a uniform electric field of magnitude 5 × 10⁴ NC⁻¹. Calculate the magnitude of the torque acting on the dipole.

Electric dipole moment, p = 4 x 10^-9 C m

Angle made by p with a uniform electric field, Θ= 30°

Electric field, E = 5 x 10⁴ N C⁻¹

Torque acting on the dipole is given by the relation,

τ = pE sinΘ = 4 x 10⁻⁹ x 5 x 10⁴ x sin 30 = 20 x 10⁻⁵ x 1/2= 10⁻⁴ Nm Therefore, the magnitude of the torque acting on the dipole is 10⁻⁴ N m.