Definition of Inductor:
Inductor is a device which can store energy in the form of magnetic field. Inductor opposes a sudden change in the flow of current. It is a component whose physical construction is simply a coil of ire . For this reason inductors are ofter called coils. The function of an inductor is to provide opposition to a changing or varying current.
Whenever a current change occurs within the coil windings, a voltage is induced across the ends of the coil. The polarity of the induced voltage is such that it opposes the current change occurring withing the coil / inductor. In more general terms, inductors are the opposite of capacitor, in that they are able to pass a dc current and block an ac current. The basic unit of inductance is the Henry (H).
Like resistors and capacitors, inductors may be either fixed or variable. Several different types of inductors are shown below . When inductors are color coded, they can be distinguished from resistors by the fact thay the fact that the first color band is always a wide silver band. The variable inductors frequently used in modern electronic equipment are adjusted by tuning a magnetic slug in and out of its core.
A Transformer is another component that can technically be defined as a inductor, because it is constructed by placing two coils in close proximity to each other. One of the main application of a transformer is to step up or step down an ac voltage. Transformers cannot step up or step down a dc voltage.