Which component is denoted by the symbol for a thermistor?

A thermistor is specifically designed to change its resistance with temperature variations, which makes it a temperature-sensitive resistor. This unique characteristic allows thermistors to be widely used in temperature sensing and control applications.

In practice, as the temperature increases, the resistance of a thermistor typically decreases (for a negative temperature coefficient thermistor), or it increases (in the case of a positive temperature coefficient thermistor). This behavior is integral to their function, allowing them to effectively monitor temperature changes and provide feedback for control systems, such as in thermometers or thermostats.

The other options—temperature resistor, voltage regulator, and current amplifier—do not accurately describe the primary function or purpose of a thermistor, as they refer to different components with entirely different roles in electronic circuits.