A) \[\vec{\tau }=\vec{P}\times \vec{E}\]
B) \[\vec{\tau }=\vec{P}.\vec{E}\]
C) \[\vec{\tau }=2(\vec{P}+\vec{E})\]
D) \[\vec{\tau }=(\vec{P}+\vec{E})\]
Correct Answer: A
Solution :
Torque \[(\tau )\] acting on the dipole in an uniform external field \[\vec{E}\] \[\tau =\]either force \[\times \] perpendicular distance \[=qE=\,2\,a\,\sin \,\theta \] \[(q\times 2a)\times E\,\,\sin \,\theta \] \[=PE\,\,\sin \,\theta \] or \[\vec{\tau }=\vec{P}\times \vec{E}\]You need to login to perform this action.
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