Potentiometer

Definition

A potentiometer is an instrument for measuring the potential (voltage) in a circuit. It can also be used as a variable resistor to adjust voltage levels.

5 Must Know Facts For Your Next Test

1. A potentiometer consists of a resistive element and a sliding contact (wiper) that taps into the resistance.
2. It is used in null measurements, where it balances out the unknown voltage against a known reference voltage.
3. The potentiometer operates on the principle that the potential drop across a uniform wire is directly proportional to its length.
4. It provides high accuracy and precision because it does not draw current from the measured circuit when balanced.
5. Potentiometers are often employed in applications like volume control in audio equipment and as position transducers.

Review Questions

• What is the primary use of a potentiometer in electrical circuits?
• Explain how a potentiometer achieves balance during null measurements.
• Why does using a potentiometer provide high accuracy in measuring voltages?

Related terms

Voltage Divider:

A simple circuit consisting of two resistors in series that divides input voltage into smaller output voltages.

Galvanometer:

An instrument used for detecting and measuring small electric currents by deflection of a needle.

Wheatstone Bridge:

A network of four resistors forming a bridge circuit, used to measure an unknown electrical resistance by balancing two legs of the bridge.