Question

State the principle on which the AC generator works. Draw a labelled diagram and explain its working.

Answer 1

A.C generator principle:

Whenever a closed coil is rotated in a uniform magnetic field about an axis perpendicular to the field, the magnetic flux linked with coil changes and an induced emf is set up across its ends.

The construction of an ac generator is shown in the figure. Initially, the coil ABCD is horizontal. The coil starts rotating clockwise and the arm AB moves up while CD moves down. By Fleming’s right hand rule, the induced current flows along ABCD. In second half rotation, the arm CD moves up and AB moves down. The induced current flows in the opposite direction that is along DCBA. Thus, an alternating current flows in the circuit.