Question

What do you mean by electric generator? Differentiate between a.c and d.c generators on the basis of construction.

Answer 1

Electromagnetic induction occurs when an electrical wire passes through a changing magnetic field.

Electric generators is a device which use electromagnetic induction to convert mechanical energy in to electrical energy.

Following are the two types of electric generators given below:-

(i) A.C. generator

(ii) D.C. generator

(i) A.C. generator:-

In an a.c. generator or alternating current generator, the electrical current periodically reverses direction.

In an a.c. generators the coil through which the current flow is fixed and the magnet is moving. The magnets north and south poles cause the current to flow in opposite directions, producing an alternating current.

In homes typically use ac generators to power small motors and common electrical appliances. some examples are vacuum cleaners, food mixers, juicers.

(ii)D.C. generator:-

In an d.c. generator or direct current generator, the electrical current flows only in one direction.

In an d.c. generators the coil through which the current flows rotates in a magnetic field.the two ends of coil attach to a commutator: different halves of a single rotating split ring. metal brushes connect this split rings to an external circuit.

The commutator balances the charges leaving and returning to the generator.resulting the current that does not change direction.

d.c. generators power very large electric motors such as those needed for subway systems.