The Magnetic Field

Magnetic fields are the fundamental mechanism by which energy is converted from one form to another in motors, generators and transformers.
Four basic principles describe how magnetic fields are used in these devices.
1. A current-carrying wire produces a magnetic field in the area around it.
2. T time-changing magnetic field induces a voltage in a coil of wire if it passes through that coil.(This is the basis of transformer action)
3. A current-carrying wire in the presence of a magnetic field has a force induced on it.(This is the basis of motor action)
4. A moving wire in the presence of a magnetic field has a voltage induces in it.(This is the basis of generator action)