Q. An electric dipole of moment $\overrightarrow{p}$ is placed normal to the lines of force of electric intensity $\overrightarrow{E}$, then the work done in deflecting it through an angle of $180^{o}$ is
A) $pE$
B) $+ 2pE$
C) $- 2pE$
D) Zero
Explanation
(d) Work done $= \int_{90}^{270}{pE\sin{\theta\ d\theta} = \left\lbrack - pE\cos\theta \right\rbrack_{90}^{270} = 0}$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.