CBSE Class 10 Answered

Dear student,

an electric generator is a device that converts  mechanical energy to  electrical energy.A  generator forces electric charges to move through an externalelectrical circuit, but it does not create electricity or charge, which is already present in the wire of its windings. It is somewhat analogous to a water pump, which creates a flow of water but does not create the water inside. The source of mechanical energy  may be a reciprocating or turbine steam engine, water falling through a turbine, or any other source of mechanical energy.

The two main parts of a generator

Mechanical:

• Rotor: The rotating part of an electrical machine
• Stator: The stationary part of an  electrical machine

Armature: The power-producing component of an electrical machine. In a  generaotr, alternator, or dynamo the armature windings generate the electric current. The armature can be on either the rotor or the stator.

• Field: The magnetic field component of an electrical machine. The magnetic field of the dynamo or alternator can be provided by either electromagnets or permanent magnets mounted on either the rotor or the stator.

Because power transferred into the field circuit is much less than in the armature circuit, AC generators nearly always have the field winding on the rotor and the stator as the armature winding. Only a small amount of field current must be transferred to the moving rotor, using  slip rings. Direct current machines necessarily have the commutator on the rotating shaft, so the armature winding is on the rotor of the machine.

Regards

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