Which component is a variable resistor used as a voltage divider?

• A. Resistor
• B. Diode
• C. Switch
• D. Potentiometer

Answer: (D)

A voltage divider splits input voltage using resistive elements in series, with the output taken at a tap. A potentiometer is a three-terminal resistor with a movable contact (the wiper) that slides along a resistive element. When you connect the ends across the supply and take the output from the wiper, you get an adjustable fraction of the input voltage. This makes it ideal for acting as a variable resistor in a voltage divider, providing a controllable output from near zero up to the full input. A simple resistor is fixed and cannot vary the division ratio without swapping components, a diode is nonlinear and not used for clean division, and a switch doesn’t provide a voltage division. So the component that fits as a variable resistor used as a voltage divider is the potentiometer.