Definition of: induction coil

Electr.
An apparatus for generating currents by electromagnetic induction, consisting usually of two concentric coils of insulated wire enclosing an iron core. One of the coils, called the primary, is usually short and of thick wire, and the secondary long and of thin wire. An alternating current of high tension is induced in the secondary coil by rapid automatic making and breaking of the circuit in the primary.
INDUCTION COIL