Which of the following actions will not lead to an increase in the induced e.m.f. in a coil of wire rotating between the poles of a magnet? Increasing the

Answer Details

Increasing the gap between the poles of the magnet will not lead to an increase in the induced e.m.f. in a coil of wire rotating between the poles of the magnet. This is because the magnetic field is weaker at a greater distance from the magnet, and therefore the rate of change of magnetic flux linking with the coil will be smaller. The induced e.m.f. is directly proportional to the rate of change of magnetic flux, so if the flux linkage decreases, the induced e.m.f. will also decrease. On the other hand, increasing the strength of the magnet, the number of turns in the coil, or the speed of rotation of the coil will all increase the rate of change of magnetic flux and hence increase the induced e.m.f.