explain about the working of a AC Generator ?

The AC generator(also known as dynamo) or alternator works on the principle of electromagnetic induction. That is when a coil is rotated in a uniform magnetic field, then current is induced in it. We convert mechanical energy into electrical energy.

Working:

When the plane of the coil remains perpendicular to the magnetic field there isn’t any emf developed. As the coil rotates in the anticlockwise direction, thus cutting the magnetic lines of force near the S-pole of the magnet the emf induced increases and current is induced. As per Flemings right-hand rule, current flows in the direction B to A in the arm AB and D to C in arm CD and the effective induced current in direction DCBA. After half rotation arm CD is on the LHS and starts moving down thus inducing current again. Now, the currents are in the direction of A to B in arm AB and C to D in the arm CD.

This current that changes direction after equal intervals of time is called alternating current and the device is called alternating(AC) generator.

AC frequency in India- 50 Hz means in every one revolution, current changes its polarity two times meaning AC produced changes polarity 100(2 ´ 50) times in one second.

Thanks & Regards,

Vasantha Sivaraj,

askIITians faculty.