A uniform current carrying ring of mass $m$ and radius $R$ is connected by a massless string as shown. A uniform magnetic field $B_0$ exist in the region to keep the ring in horizontal position, then the current in the ring is ($l =$ length of string)
A$\frac{{mg}}{{\pi R{B_0}}}$
B$\frac{{mg}}{{R{B_0}}}$
C$\frac{{mg}}{{3\pi R{B_0}}}$
D$\frac{{mgl}}{{\pi {R^2}{B_0}}}$
Medium
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A$\frac{{mg}}{{\pi R{B_0}}}$
a $\tau_{\text {net }}=0 ; \mathrm{mgR}=\mathrm{MB}_{0}(\mathrm{M}=$ magnetic dipole moment);
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