Contents
Key Stage 4
Meaning
A thermistor is a resistor which changes resistance depending on the temperature.
About Thermistors
- 'NTC' thermistors decrease resistance as the temperature increases. (NTC = Negative Temperature Coefficient.)
- A thermistor can be used to control the current passing through a circuit. If the potential difference is constant then the current decreases as temperature decreases.
- A thermistor can be used to control the potential difference of another component in series with it. If the temperature is decreased then the potential difference across other components will decrease.
- Thermistors can be used temperature sensors.
IV Graph
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Description
The IV Graph for an 'NTC' thermistor shows that:
- At a high temperature the current increases rapidly with the potential difference
- At a low temperature the current increases slowly with the potential difference.
Explanation
- The resistance of an 'NTC' thermistor increases as the temperature decreases.