Describe the working of an AC generator with the help of a labelled circuit diagram. What changes must be made in the arrangement to convert it to a DC generator?

Explanation

The working of an AC generator is as follows

As the coil rotates, the two rings also rotate with the coil. The brushes P and Q keep contact with the rotating ring. When the coil starts rotating with arm AB moving up and CD moving down (clockwise ) cutting the magnetic lines. According to Flaming's right-hand rule, the current is induced in these arms in the direction ABCD.
After half rotation, arm CD moves down and AB moves up. As a result, dierction of current in each segment changes, giving rise to net induced current in the direction DCBA. Thus, after every rotation, polarity of current in the respective arm changes , thereby generation direct current.
To convert an AC generator into a DC generator, a split ring commutator is used. This helps in producing direct current.