How does a transformer work

When an AC flows through the primary coil in a transformer it produced a magnetic field which magnetises the iron core Due to the AC, the magnetic field in the iron core alternates. This constantly changing field cuts through the secondary coil The changing field induces an alternating potential difference across the ends of teh secondary coil by the generator effect If the secondary coil is part of a complete sicruit, this pd causes an ac to flow, it has the same frequency as the atlernating current in the primary coil