Figure 28. 10 shows a current loop in an external magnetic field and the forces exerted on the different lengths of the wire. Assume that the loop is attached to a pivot that allows it to spin (as between Figures 28. 10 and 28. 11).

(a) Determine the directions of all the forces on the loop if the current were reversed.

(b) Is this new situation any different from that shown in Figure 28. 11?

Data from  Figure P28.10

Data from  Figure P28.11

Force exerted by magnetic field on top and bottom sides of current-carrying loop... B ...creates torque that tends to rotate loop.