Two small spherical balls of mass 10 g each with charges \(-2\mu \mathrm{C}\) and \(2\mu \mathrm{C}\), are attached to t…

Two small spherical balls of mass 10 g each with charges \(-2\mu \mathrm{C}\) and \(2\mu \mathrm{C}\), are attached to two ends of very light rigid rod of length 20 cm . The arrangement is now placed near an infinite nonconducting charge sheet with uniform charge density of \(100\mu \mathrm{C}/{\mathrm{m}}^{2}\) such that length of rod makes an angle of \(30^\circ\) with electric field generated by charge sheet. Net torque acting on the rod is:
(Take \({\epsilon }_{0}:8.85\times {10}^{-12}{\mathrm{C}}^{2}/{\mathrm{Nm}}^{2}\))