The lower end of the thin uniform rod in Fig. $\mathbf{P 2 7 . 7 2}$ is attached to the floor by a frictionless hinge at point $P$. The rod has mass $0.0840 \mathrm{~kg}$ and length $18.0 \mathrm{~cm}$ and is in a uniform magnetic field $B=0.120 \mathrm{~T}$ that is directed into the page. The rod is held at an angle $\theta=53.0^{\circ}$ above the horizontal by a horizontal string that connects the top of the rod to the wall. The rod carries a current $I=12.0 \mathrm{~A}$ in the direction toward $P$. Calculate the tension in the string. Use your result from Problem 27.66 to calculate the torque due to the magnetic-field force.