Chapter 30, Problem 73PQ

A circular coil 15.0 cm in radius and composed of 145 tightly wound turns carries a current of 2.50 A in the counterclockwise direction, where the plane of the coil makes an angle of 15.0° with the y axis (Fig. P30.73). The coil is free to rotate about the z axis and is placed in a region with a uniform magnetic field given by $\stackrel{\to }{\text{B}}=\text{ 1}\text{.35}\hat{\text{j}}\text{ T}$. a. What is the magnitude of the magnetic torque on the coil? b. In what direction will the coil rotate?

FIGURE P30.73