In a circuit, what does a negative temperature coefficient thermistor typically indicate?

A negative temperature coefficient (NTC) thermistor is a type of resistor whose resistance decreases as the temperature increases. This property makes NTC thermistors particularly useful in various applications such as temperature sensing or circuit protection.

When the temperature rises, the thermal energy increases, which allows more charge carriers in the thermistor material to move, resulting in lower resistance. Conversely, as the temperature decreases, the resistance increases. This characteristic is key in applications like temperature measurement, where the resistance value can be calibrated to correspond precisely to a specific temperature range.

The other choices do not align with the behavior of NTC thermistors. For instance, a thermistor that shows increased resistance with temperature would be a positive temperature coefficient thermistor, which is not the case here. Constant resistance regardless of temperature or resistance that is independent of temperature changes does not reflect the fundamental properties of an NTC thermistor.