Potentiometer

A potentiometer is a device that uses a three-terminal resistor with one movable contact, called the wiper, to function as a variable voltage divider. When only two terminals are connected, the potentiometer operates as a variable resistor or rheostat. In the model, terminals A and C are connected to a power supply, while terminals B and C are connected to a light bulb. The resistive material inside the potentiometer is commonly made of graphite, though other materials such as resistance wire or carbon particles embedded in plastic are also used. In a linear potentiometer, the wiper moves along a straight resistive path, as opposed to the circular movement in rotary potentiometers. The wiper (terminal B) slides along the resistive material, altering the resistance on either side of it. As the wiper approaches terminal A, the voltage at the wiper increases. Conversely, as it moves closer to terminal C, the voltage decreases. This change in voltage affects the current flowing through the light bulb, consequently adjusting its light intensity.