Q 12-01-019NEETJEE MainMedium
An electric dipole of moment $p$ is placed in a uniform electric field $E$ with its axis at $30°$ to the field. The torque on it is
Answer: (C) $\dfrac{pE}{2}$
Concept. Torque on a dipole: $\tau = pE\sin\theta$ (the net force is zero in a uniform field).
Step 1. Substitute. $\tau = pE\sin30° = \dfrac{pE}{2}$.
Answer. $\dfrac{pE}{2}$ (Option C).
Solution by Sreeraj P, M.Sc Physics