Question 739: Electrostats & Capacitance

Question

Two electric dipoles of dipole moments $$1.2 	imes 10^{-30} \,\mathrm{Cm}$$ and $$2.4 	imes 10^{-30} \,\mathrm{Cm}$$ are placed in two different uniform electric fields of strengths $$5 	imes 10^{4} \,\mathrm{NC}^{-1}$$ and $$15 	imes 10^{4} \,\mathrm{NC}^{-1}$$ respectively. The ratio of maximum torque experienced by the electric dipoles will be $$\frac{1}{x}$$. The value of $$x$$ is __________.

Accepted Answer

$${{{ho _1}} \over {{ho _2}}} = {{{\mu _1}{B_1}\sin 90} \over {{\mu _2}{B_2}\sin 90}}$$
$$ = {{1.2 	imes {{10}^{ - 30}} 	imes 5 	imes {{10}^4}} \over {2.4 	imes {{10}^{ - 30}} 	imes 15 	imes {{10}^4}}}$$
$$ = {1 \over 6}$$

Electrostats & Capacitance

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