An automation system monitors the electrical current drawn by a bank of identical solenoid valves connected in parallel. The operating potential difference across the parallel network is maintained at a constant value. The table below displays the measurements recorded during a calibration test:
| Number of active valves | Total current in mA | Potential difference in V |
|---|---|---|
| 1 | 24.0 | 18.00 |
| 2 | 48.0 | 18.00 |
| 3 | 72.0 | 18.00 |
| 4 | 96.0 | 18.00 |
Using data from the table, calculate the electrical resistance of only 1 solenoid valve.
59 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.