Operation of DC generator

Answer 1

1) PRINCIPLE:

Whenever a conductor cuts magnetic flux, dynamically induced emf is produced in it. ( Faraday's Laws of Electromagnetic Induction ). This emf causes a current to flow if the conductor circuit is closed.

2 ) OPERATION:

Field winding produces magnetic field in D.C. generator. Armature is coupled to the prime mover. Prime mover produces torque so the armature rotates. The armature cuts the magnetic field so the emf is induced in the armature. When load is connected to the armature, electric current flows from the armature conductors, through load and back to the armature conductors. Now, as current flows through the armature and it is in the magnetic field, torque is produced due to it. (This torque is called back torque). If the load on the generator is increased, the back torque increases so the torque of the prime mover also increases and the input power to the prime mover increases. In this way, the generator converts mechanical energy into electrical energy.

It should be observed that the emf induced in D.C. generator, is A.C. ( so the emf induced in the armature is alternating in nature. ). Then with the help of commutator, it is converted into D.C. Rings and brushes are used to take the emf outside.