Text: A term having very broad application in electricity and radio. It may be used to designate any arrangement of a number of turns of wire usually copper, and used for almost any purpose in the production of electric and magnetic effects or phenomena. The most common significance of a "coil" in radio is in reference to a number of turns of insulated wire wound on various forms and used for tuning (q.v.). The term inductance coil is generally used, although actually, any coil of wire will have inductance. Coils come in countless numbers and variety for many purposes. A coil may be used not alone for tuning ‹ that is to adjust a receiver or transmitter to resonance with incoming or outgoing signals; it may be used to connect two circuits, in which ease it is known as a coupling coil; it may be used with a core (q.v.) of iron wire, or laminated pieces, as a choke coil (q.v.) or it may be used in connection with high frequency apparatus, such as used by physicians. Coils are generally referred to by individual names indicating their construction or use.

See Also:

Source: 190