Variable Resistor Symbol

A variable resistor, also called an adjustable resistor, consists of two terminals, where one of the terminals is a sliding or moving contact often known as a wiper. This is an IEC international symbol of such a device.

Potentiometer

The potentiometer symbol is very similar to the variable resistor symbol; however, it is a three terminal device. When all three terminals are used in a circuit, it behaves as a potential divider across the voltage rails. However when only two of its terminals are used, specifically the slider terminal (wiper) and one of the fixed terminals, then it behaves as a variable resistor. Usually, electronic shops sell variable resistors as potentiometers, which are three terminal devices, and you simply use two of the mentioned terminals.

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