a.c. Motors

Abstract

Imagine that you are looking at the end of the conductor in Figure 15.1(a) when the S-pole of a permanent magnet is suddenly moved from left to right across the conductor. By applying Fleming’s right-hand rule, you can determine the direction of the induced e.m.f. and current in the conductor. You need to be careful when applying Fleming’s rule in this case, because the rule assumes that the conductor moves relatively to the magnetic flux (in this case it is the flux that moves relatively to the conductor, so the direction of the induced e.m.f. is determined by saying that the flux is stationary and that the conductor effectively moves to the right). You will find that the induced current flows away from you.