What happens to the resistance of a negative temperature coefficient (NTC) thermistor when the temperature increases?

A negative temperature coefficient (NTC) thermistor is designed to have resistance that decreases as temperature increases. This is a characteristic of NTC thermistors, which are widely used in temperature sensing and control applications.

When the temperature rises, the increased thermal energy allows charge carriers (electrons or holes) in the thermistor material to move more freely. This results in a reduction in the material's resistance. The thermistor’s behavior is crucial in applications such as temperature monitoring and circuit protection, making it a valuable component in HVAC systems and other electronic devices.

In contrast, the resistance of a positive temperature coefficient (PTC) thermistor increases with temperature, but that is outside the scope of this question. Other options, such as the resistance remaining the same, increasing, or fluctuating, do not align with the fundamental electrical properties of an NTC thermistor. Therefore, recognizing that NTC thermistors decrease in resistance with increasing temperature is essential for understanding how to apply them in practical situations.