Inductance

Along with capacitors, inductors still make up a very important part of modern day circuitry. Often, the two are used in conjunction to great effect.

Inductors usually consist of an electric current passing through a coil of wire. The coil may be in a circular or straight shape itself. The purpose of an inductor is to store voltage via a magnetic field in the coil, according to Faraday's Law of electromagnetic induction.

Nowadays, inductors are often used to remove the mains hum of an AC current. This hum can vibrate the circuit, obstructing power lines, and can usually be easily heard, so the inductor coupled with a capacitor reduces the hum. Similarly, they can be used to reduce electromagnetic interference. EMI is the interference outside sources of electromagnetic power exert on a circuit, and can ruin a good circuit rather easily. Inductors help to negate this interference so that the electricity can pass normally and the circuit will function Inductors can also convert AC current to DC.

Sadly, inductors are now being phased out due to their various side effects over extended use. However, one can't deny their important contribution to modern circuitry!