An electric dipole is placed at an angle of $30^{\circ}$ with an electric field of intensity $2 im

Question

An electric dipole is placed at an angle of $30^{\circ}$ with an electric field of intensity $2 	imes 10^{5} \mathrm{~N} \mathrm{C}^{-1}$. It experiences a torque equal to 4 Nm . Calculate the magnitude of charge on the dipole, if the dipole length is 2 cm .

Professor PC Thomas Classes · Answer

Given, angle, $	heta=30^{\circ}$,

Electric field intensity, $E=2 	imes 10^{5} \mathrm{NC} \mathrm{C}^{-1}$
$	au=4 \mathrm{Nm}$, Dipole length, $l=2 \mathrm{~cm}=0.02 \mathrm{~m}$
$	au=p E \sin 	heta=(q l) E \sin 	heta$
$	herefore \quad q=\frac{	au}{E l \sin 	heta}=\frac{4}{2 	imes 10^{5} 	imes 0.02 	imes \frac{1}{2}}=2 \mathrm{mC}$