A circular coil with area A and N turns is free to rotate about a diameter that coincide...

A circular coil with area A and N turns is free to rotate about a diameter that coincides with the x-axis. Current I is circulating in the coil. There is a uniform magnetic field in the positive y-direction. Calculate the magnitude and direction of the torque and the value of the potential energy U, as given in Eq. (27.27), when the coil is oriented as shown in parts (a) through (d) of Fig. E27.45.