Throttle Potentiometers:

A potentiometer is an instrument for measuring the potential (or voltage) in a circuit taps off a fraction of a known voltage from a resistive slide wire and compares it with the unknown voltage. It is a three-terminal resistor with a sliding contact that forms an adjustable voltage divider. If only two terminals are used (one side and the wiper), it acts as a variable resistor or Rheostat. Potentiometers operated by a mechanism can be used as position transducers. They are used to control the electrical devices such as electrical devices such as a volume control of a radio.

Throttle Potentiometers