A technician is making a resistor for a circuit by winding resistance wire into a coil. The wire must have the same material and cross-sectional area as a sample wire, and both wires are at the same temperature.
| Wire or requirement | Length | Potential difference | Current |
|---|---|---|---|
| Sample wire | 0.40 m | 2.0 V | 0.50 A |
| Coil resistor | To be calculated | 3.0 V | 0.30 A |
Calculate the length of wire needed for the coil resistor.
82 exam-style questions on AQA GCSE Physics 2.1 Current, potential difference and resistance, covering 2.1.1 Standard circuit diagram symbols, 2.1.2 Electrical charge and current, 2.1.3 Current, resistance and potential difference, and 2.1.4 Resistors. Each one has a worked solution and a mark scheme showing where the marks go.