Inductor
A passive component designed to resist changes in current,inductors are often referred to as “AC Resistor”,the ability to resist changes in current and the ability to store energy in its magnetic field,account for the bulk of the useful properties of inductors,current passing through an indutor will produce a mangetic field, a changing magnetic field induces a voltage which opposes the field-producing current,this property of impeding changes of current is known as inductance, the voltage induced across an inductor by a change of current is defined as: V=Ldi/dt, thus, the induced voltage is proportional to the inductance value and the rate of current change.