Question

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

(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 (p⃗) is kept in a uniform electric field E⃗. Show graphically the variation of torque acting on the dipole (τ) with its orientation (θ) in the field. Find the orientation in which torque is (i) zero and (ii) maximum.

An electric dipole with dipole moment P = P₀î − P₀ĵ is placed in an electric field E = E₁î + E₂ĵ, where P₀, E₁ and E₂ are constants. The torque acting on the dipole is :