Browse Questions

An electric dipole of moment $\;\overrightarrow{P}\;$ is lying along a uniform electric field $\;\overrightarrow{E}\;$ The work done in relating the dipole by $\;90^{0}\;is$

$(a)\;PE\qquad(b)\;\sqrt{2} PE\qquad(c)\;\large\frac{PE}{2}\qquad(d)\;2PE$

Explanation :
Work done = $\Delta P .E$
$P . E = -\overrightarrow{P} . \overrightarrow{E}$
$P . E_{f}=0$
$P . E_{i} = -P E$
$\Delta P . E=P E=work done\;.$