Suppose the square current loop in Figure 28.10 is replaced by a circular loop with a diameter equal to the width of the square loop and with the same current. Does the circular loop experience a torque? If not, why not? If so, how does this torque compare with that on the square loop?

Figure 28.10 Magnetic forces exerted on a square current loop that is oriented so that its magnetic dipole moment is perpendicular to an external magnetic field. Force exerted by magnetic field on top and bottom sides of current-carrying loop... B TE creates torque that tends to rotate loop. FB