Question

An electric dipole has a fixed dipole moment p, which makes angle θ with respect to X-axis. When subjected to an electric field E1 = E(cap)i, it experiences a torque T1 = τ(cap)k. When subjected to another electric field E2 = √3E1(cap)j, it experiences a torque T2 = - T1. The angle θ is

(a) 45°

(b) 60°

(c) 90°

(d) 30°

Answer 1

Correct Option (b) 60°

Explanation:

Torque applied on a dipole τ = ρE sin θ

where, θ = angle between axis of dipole and electric field

For electric field E1 = E(cap)i

it means field is directed along positive X direction, so angle between dipole and field will remain θ, therefore torque in this direction