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An electric dipole of moment $\overrightarrow{\mathrm{p}}$. is lying along a uniform electric field $\overrightarrow{\mathrm{E}} \cdot$ The work done in rotating the dipole through $90^{\circ}$ is
$\left[\sin 0^{\circ}=\cos 90^{\circ}=0, \cos 0^{\circ}=\sin 90^{\circ}=1\right]$
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$\left[\sin 0^{\circ}=\cos 90^{\circ}=0, \cos 0^{\circ}=\sin 90^{\circ}=1\right]$
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Verified Answer
The correct answer is:
$\mathrm{pE}$
Work done $=\Delta \mathrm{pE}$
$\begin{aligned} & \mathrm{pE}=-\overrightarrow{\mathrm{p}} \overrightarrow{\mathrm{E}} \\ & \mathrm{pE}_{\mathrm{f}}=0 \\ & \mathrm{pE}_{\mathrm{i}}=-\mathrm{pE} \\ & \Delta \mathrm{pE}=\mathrm{pE}\end{aligned}$
$\begin{aligned} & \mathrm{pE}=-\overrightarrow{\mathrm{p}} \overrightarrow{\mathrm{E}} \\ & \mathrm{pE}_{\mathrm{f}}=0 \\ & \mathrm{pE}_{\mathrm{i}}=-\mathrm{pE} \\ & \Delta \mathrm{pE}=\mathrm{pE}\end{aligned}$
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