Question

With the help of a diagram, briefly explain the construction and working of an AC generator.

Hint:

An AC generator produces an alternating voltage, which is converted to DC using a commutator in a DC generator.

Answer 1

Construction and Working of an AC Generator 

Construction of an AC Generator
An AC generator converts mechanical energy into electrical energy based on electromagnetic induction. 

It consists of: 
1. Armature Coil (\( ABCD \)): A rectangular coil rotates inside a magnetic field.
2. Magnetic Field: Created using permanent magnets or electromagnets.
3. Slip Rings (\( S_1, S_2 \)): Connected to the coil, providing continuous contact.
4. Brushes: Connect the slip rings to the external circuit. 

 Working of an AC Generator
- The coil rotates in the magnetic field due to external mechanical energy.
- According to Faraday’s Law of Electromagnetic Induction, an EMF is induced: \[ \mathcal{E} = B L v \sin\theta \] - The induced current alternates because the coil changes orientation every half cycle.
- The output AC voltage follows: \[ \mathcal{E} = \mathcal{E}_0 \sin \omega t \]