Question

What is the working principle of an alternating current generator? Describe its construction and working method with the help of a diagram.

Hint:

The AC generator produces alternating current by rotating a coil within a magnetic field, reversing the direction of the induced current periodically.

Answer 1

Working Principle of an AC Generator:
An alternating current (AC) generator works on the principle of electromagnetic induction. According to Faraday's Law of Induction, when a conductor moves through a magnetic field, an electromotive force (EMF) is induced in the conductor. This induced EMF causes current to flow. The direction of the induced current changes when the direction of motion of the conductor or the magnetic field is reversed, producing alternating current.
Construction of an AC Generator:
1. Armature: The armature is the rotating coil of wire, which cuts the magnetic field lines to induce an EMF.
2. Magnetic Field: A strong magnetic field is provided by either permanent magnets or electromagnets.
3. Slip Rings: Slip rings are used to provide a continuous connection between the rotating armature and the external circuit.
4. Brushes: Carbon brushes maintain contact with the slip rings and transfer the current from the rotating armature to the external circuit. 5. Axis: The armature is mounted on a shaft, which rotates to cut through the magnetic field.
Working Method of an AC Generator:
1. As the armature rotates, it cuts the magnetic field lines, and an EMF is induced in the coil according to Faraday’s Law.
2. The induced EMF causes alternating current to flow through the external circuit.
3. The current alternates its direction as the armature continues to rotate, producing an alternating current (AC).
Conclusion:
Thus, an AC generator converts mechanical energy into electrical energy by using the principle of electromagnetic induction.