A student measures the resistance of a thermistor at different temperatures.
The Table shows the results.
Table
| Temperature in ∘C^{\circ}\text{C}∘C | Resistance in Ω\OmegaΩ |
|---|---|
| 10 | 480 |
| 20 | 300 |
| 30 | 190 |
| 40 | 120 |
| 50 | 80 |
Describe the relationship between the temperature and the resistance of the thermistor.
The thermistor is connected to a 5.7 V power supply.
Calculate the current in the thermistor when its temperature is 30 ∘C30\ ^{\circ}\text{C}30 ∘C.
The temperature of the thermistor changes.
The current in the thermistor is now 0.019 A. The potential difference across it is still 5.7 V.
Determine the new temperature of the thermistor.
The thermistor is used in a circuit that sets off a fire alarm.
Explain how the current in the thermistor changes if a fire heats the thermistor.
81 exam-style questions on Edexcel GCSE Physics 10.2 Resistance, covering 10.2.1 Current in a circuit and conservation at junctions, 10.2.2 Resistance and variable resistors, 10.2.3 Series and parallel resistance, 10.2.4 I–V characteristics of components, and 10.2.5 LDRs and thermistors. Each one has a worked solution and a mark scheme showing where the marks go.