9.3.8—The resistance of a thermistor decreases as the temperature increases (it
- Syllabus
- 9702–2028–2029
- Objective
- 9.3.8
- Level
- AS
An NTC thermistor has lower resistance as temperature rises
For an NTC thermistor, resistance decreases when temperature increases because carrier availability and scattering conditions change in the semiconductor.
The sensor direction must be combined with circuit topology to predict whether an output voltage rises or falls.
In a divider with the thermistor on top, heating it lowers its resistance and lowers the output across it.
“Thermistor resistance decreases” is not enough to predict a voltage without specifying which voltage is measured and where the thermistor sits.
ConceptA-Level CAIE Physics AS