Alternating Current Generator
The basic principle of an AC generator is shown in Figure 1. The coil ends are connected to two slip rings.
As the coil sides A and B are rotated by an external force side A will have an EMF induced first in one direction and then in the other direction.
As side A of the coil is permanently connected to one slip ring, this ring will alternate from positive to negative as coil side A rotates past the North and South pole faces. The same process applies to coil side B. The generated output is therefore alternating ( AC ).
The direction of the induced EMF in each coil side can be determined by the use of Fleming’s Right Hand Rule.