question_answer 70)

  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 into a DC generator?

Answer:

                  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 Fleming'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, the direction of current in each segment changes, giving rise to net induced current in the direction DCB.4. Thus, after every rotation, polarity of current in the respective arm changes, thereby generating an alternating current. To convert an AC generator into a DC generator, a split ring commutator is used. This helps in producing direct current.