A potentiometer, called pot for short, is an electrical component that acts as a variable voltage divider. They usually have three terminals, one of which is connected to a moving center contact. A potentiometer with two terminals is a variable resistor, called a rheostat. Potentiometers come in many forms including rotaries, trimmers, sliders.
Potentiometer is also the term for an old instrument that measured an unknown voltage after being calibrated with a known voltage. These have been replaced by multimeters today.
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