How generator can produce alternating current?

Question

How generator can produce alternating current?

Answer 1

An AC "generator" works by rotating a coil through a magnetic field (or vice-versa). To make a DC generator, the AC current is switched - commutated - to make it one polarity.  AC devices have no such commutation and pass the resulting coil current directly. (First link below.)

Commutation into DC can be done through brushes on the rotor or through rectification diodes. In car guy terms, the terms "generator" and "alternator" distinguish between the two types: fixed-field and brushes ("generator") vs. moving-field and diodes ("alternator") type. But they're both DC generators (second and third links below).

Answer 2

this is accomplished by rotating the magenet N-S inside a stationary coil of wire.The alternating N-S/S-N poles,reverse the electron flow as the magnetic field reverses.Hence "alternates". Go to how stuff works.com

there is an excelent animation of how it works.