A(n) ___ is a variable-resistance electric device that divides voltage proportionally between two circuits.

A(n) ___ is a variable-resistance electric device that divides voltage proportionally between two circuits.

• A. Rectifier
• B. Inverter
• C. Pulse Width Modulator
• D. Potentiometer

Answer: (D)

A potentiometer is a three-terminal variable resistor that acts as a voltage divider. The resistive element has a fixed total resistance, and a movable contact (the wiper) taps off a portion of that resistance. If you apply a source across the two end terminals and use the wiper as the output, the voltage you get is a fraction of the input that depends on the wiper position. As you turn the knob, that fraction changes, so the device divides the voltage proportionally between the two parts of the circuit it’s connected to. This is why potentiometers are used to adjust levels like volume or sensor calibration. The other devices don’t provide this proportional voltage division: a rectifier converts AC to DC, an inverter converts DC to AC, and a pulse width modulator controls average voltage by switching rather than dividing it.

A potentiometer is a three-terminal variable resistor that acts as a voltage divider. The resistive element has a fixed total resistance, and a movable contact (the wiper) taps off a portion of that resistance. If you apply a source across the two end terminals and use the wiper as the output, the voltage you get is a fraction of the input that depends on the wiper position. As you turn the knob, that fraction changes, so the device divides the voltage proportionally between the two parts of the circuit it’s connected to. This is why potentiometers are used to adjust levels like volume or sensor calibration. The other devices don’t provide this proportional voltage division: a rectifier converts AC to DC, an inverter converts DC to AC, and a pulse width modulator controls average voltage by switching rather than dividing it.