College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 74

A magnetic field exerts a torque on each of the current carrying single loops of wire shown in Figure CQ19.19. The loops lie in the xy -plane, each carrying the same magnitude current, and the uniform magnetic field points in the positive x -direction. Rank the coils by the magnitude of the torque exerted on them by the field, from largest to smallest. (a) A, B, C (b) A, C, B (c) B, A, C (d) B, C, A (e) C, A, B