An electronic component that is used to vary the amount of current that flows through a circuit. It works by sliding a wiper terminal across a resistive material, typically a thin film or chunk of carbon or a resistive wire made of nickel chromium or tungsten alloys. After being set to the appropriate location, the wiper's position often remains fixed on the circuit board; however, it can also be made user adjustable with a screwdriver.Pots and RheostatsPotentiometers and rheostats are variable resistors in which the wiper terminals take the form of a dial or slider that the user does manipulate, such as the volume control of a radio or music system. A rheostat is similar to a potentiometer, but handles more power. See resistor.