Question

A dipole comprises of two charged particles of identical magnitude q and opposite in nature. The mass ‘m’ of the positive charged particle is half of the mass of the negative charged particle. The two charges are separated by a distance ‘l’. If the dipole is placed in a uniform electric field ‘\(\vec{E}\)’ ; such a way that dipole axis makes a very small angle with the electric field, ‘\(\vec{E}\)’. The angular frequency of the oscillations of the dipole when released is given by

(A) \(\sqrt{\frac{8qE}{3ml}}\)

(B) \(\sqrt{\frac{4qE}{ml}}\)

(C) \(\sqrt{\frac{3qE}{2ml}}\)

(D) \(\sqrt{\frac{8qE}{ml}}\)

Answer 1

Correct option is (C) \(\sqrt{\frac{3qE}{2ml}}\)

If released, it will oscillate about centre of mass. For small ‘θ'

τ = -PE. θ