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

AC Generator: Construction and Operation

AC Generator Construction
An AC generator transforms mechanical energy into electrical energy via electromagnetic induction. 

Key components include: 
1. Armature Coil (\( ABCD \)): A rectangular coil that rotates within a magnetic field.
2. Magnetic Field: Generated by permanent magnets or electromagnets.
3. Slip Rings (\( S_1, S_2 \)): These are attached to the coil, ensuring continuous electrical contact.
4. Brushes: They link the slip rings to the external circuit. 

 AC Generator Operation
- External mechanical force causes the coil to rotate within the magnetic field.
- An EMF is induced as per Faraday’s Law of Electromagnetic Induction: \[ \mathcal{E} = B L v \sin\theta \] - The induced current alternates due to the coil's changing orientation each half-cycle.
- The output AC voltage is described by: \[ \mathcal{E} = \mathcal{E}_0 \sin \omega t \]