Answer:
Torque experienced by the electric dipole of dipole moment \[\vec{p}\] in a uniform electric field \[\vec{E}\] is given by \[\vec{\tau }=\vec{p}\times \vec{E}\] The pairs of perpendicular vectors are: (i) When \[\theta ={{90}^{\circ }}\], torque is maximum [Fig. (a)]. \[{{\tau }_{\max }}{{=}_{p}}E\sin {{90}^{\circ }}=pE\] (ii) When\[\theta ={{30}^{\circ }}\]\[{{150}^{\circ }}\] torque is half the maximum value [Fig. (b)]. \[\tau {{=}_{p}}E\sin ({{30}^{\circ }}\text{or 15}{{\text{0}}^{\circ }})\] \[=\frac{1}{2}pE=\frac{1}{2}{{\tau }_{\max }}\] (iii) When \[\theta ={{0}^{\circ }}\]or\[~\text{18}0{}^\circ \], torque is minimum [Fig. (c)] \[{{\tau }_{\min }}=pE\sin ({{0}^{\circ }}or{{180}^{\circ }})=0\]
You need to login to perform this action.
You will be redirected in
3 sec