Potentiometer

A potentiometer ( /pɵˌtɛnʃiˈɒmɨtər/), informally a pot, is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used, one end and the wiper, it acts as a variable resistor or rheostat.

A potentiometer measuring instrument is essentially a voltage divider used for measuring electric potential (voltage); the component is an implementation of the same principle, hence its name.

Potentiometers are commonly used to control electrical devices such as volume controls on audio equipment. Potentiometers operated by a mechanism can be used as position transducers, for example, in a joystick. Potentiometers are rarely used to directly control significant power (more than a watt), since the power dissipated in the potentiometer would be comparable to the power in the controlled load.

Read more about Potentiometer:  Potentiometer Construction, Rheostat, Digital Potentiometer, Membrane Potentiometer, Potentiometer Applications, Theory of Operation, Early Patents