Talk:Potentiometers are Variable Resistors

rheostat and potentiometer

rheostat: A continuously variable electrical resistor used to regulate current.

potentionmeter: An instrument for measuring an unknown voltage by comparison to a standard voltage.

A potentiometer is a three terminal device. A rheostat is a two terminal device. A potentiometer is hooked as a variable voltage divider. The resistance across the outer terminals is constant. It changes the potential, the voltage. A rheostat is hooked as a variable resistance. It varies the current.

A potentiometer can be connected as a rheostat by leaving one of the terminals unconnected.