How does a potentiometer work in a circuit?

A potentiometer operates as a variable resistor, allowing the user to adjust its resistance manually. When the resistance of the potentiometer is changed, it directly influences the voltage drop across it, effectively controlling the voltage or current that flows in the circuit. This is particularly useful in applications such as volume controls in audio devices, where adjusting the potentiometer alters the output to desired levels.

The ability to vary resistance is integral to how a potentiometer functions, enabling it to provide a continuous adjustment within a specified range. This mechanism is different from merely measuring resistance or automatically adjusting voltage based on current, both of which do not reflect the primary function of a potentiometer. Additionally, potentiometers do not store energy; instead, they dissipate electrical energy as heat due to resistance, making option B the most accurate representation of how a potentiometer works in a circuit.