A resistor in a temperature-monitoring circuit has a constant resistance. The table shows readings taken at three supply settings.
| Potential difference / V\mathrm{V}V | Current / mA\mathrm{mA}mA |
|---|---|
| 2.0 | 40 |
| 5.0 | 100 |
| 8.0 | 160 |
What potential difference would produce a current of 140 mA?
7.0 V7.0\ \mathrm{V}7.0 V
3.6 V3.6\ \mathrm{V}3.6 V
2.8 V2.8\ \mathrm{V}2.8 V
8.0 V8.0\ \mathrm{V}8.0 V
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.