Physics - Magnetism Question with Solution | TestHub

The magnetic field is perpendicular to the plane of the paper. Let us consider two diametrically opposite elements. By Fleming's Left hand rule on element AB the direction of force will be Leftwards and the magnitude will be $dF=\mid dlB\sin 90^{\circ }=IdlB$
On element $\mathrm{CD}$, the direction of force will be towards right on the plane of the papper and the magnitude will be $\mathrm{dF}=\mathrm{Id}/\mathrm{B}$.