Which component is a resistor used to compensate for temperature variations in a circuit?

• A. Transformer
• B. Tachometer
• C. Thermistor
• D. Servomechanism

Answer: (C)

A thermistor is used to compensate for temperature variations because it is a resistor whose value changes with temperature in a predictable way. By selecting an NTC (resistance decreases as temperature rises) or a PTC (resistance increases with temperature) type and placing it in the circuit where temperature drift would affect performance, you offset those changes and keep biasing or operating points more stable as the temperature changes. The other components serve different primary roles—transformers alter voltage, tachometers measure speed, and servomechanisms are control devices—so they aren’t used for temperature compensation through a temperature-sensitive resistance.