The function of the coil in an AC generator is to cut the magnetic field lines as it rotates, inducing an alternating current.
In a simple AC generator, the key components work together to produce electricity. As detailed in the Cambridge (CIE) IGCSE Physics Revision Notes, the rotating coil has a crucial function.
Specifically, the purpose of the coil is:
- To cut the magnetic field as it rotates: The coil is placed within a magnetic field, typically provided by permanent magnets. As the coil spins, its wires move through these magnetic field lines.
- And allow an induced current to flow: According to Faraday's law of electromagnetic induction, the changing magnetic flux through the coil due to its rotation induces an electromotive force (EMF), which in turn drives an alternating current in the coil.
This induced alternating current is then conducted to the external circuit through slip rings and brushes, providing electrical energy. The faster the coil rotates or the stronger the magnetic field, the larger the induced current and voltage will be.
