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Question
Write the expression for the torque \[\vec{\tau}\] acting on a dipole of dipole moment \[\vec{p}\] placed in an electric field \[\vec{E}\].
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Solution
The torque \[\vec{\tau}\] acting on a dipole of dipole moment \[\vec{p}\] placed in an electric field \[\vec{E}\] is given by
\[\tau^\rightharpoonup = \vec{p} \times E^\rightharpoonup \]
\[\text { or }\]
\[ \tau^\rightharpoonup = pE\sin\theta\]
\[\text { where } \]
\[\theta = \text { Angle between dipole moment and electric field }\]
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