Question #43873

A rigid circular wire loop of mass $M$ and radius $R$ carries a steady current $I = \frac{7 M g}{3 \pi R B_0}$. The loop is suspended from a fixed horizontal frictionless hinge (aligned with the $x$-axis) attached to a point on its circumference. Initially, the loop hangs vertically at rest in the $xy$-plane, with the hinge at the origin and the center of the loop at $(0, -R, 0)$. A uniform magnetic field $\vec{B} = B_0 \hat{j}$ is suddenly switched on. The direction of the current is such that the initial magnetic moment of the loop is in the $+z$-direction. The magnetic torque causes the loop to swing out of the $xy$-plane. Find the maximum radial tension (the force component along the diameter passing through the hinge) exerted by the hinge on the loop during its subsequent motion.