A fuse is fitted in the live wire of a mains-powered greenhouse ventilation fan. The fuse wire is thinner than the other wires in the circuit.
Why is the fuse wire made thinner than the other wires?
It has the greatest resistance, so it heats up fastest when current flows.
It has a lower resistance, so it carries the normal current with less energy loss.
It takes a larger share of the supply potential difference, leaving less across the fan.
It makes the current in the fan larger, so the fan starts more quickly.
81 exam-style questions on Edexcel GCSE Physics 10.4 Mains electricity, covering 10.4.1 Direct and alternating current, 10.4.2 Live, neutral and earth wires; safety, 10.4.3 Mains wire potential differences and dangers, and 10.4.4 Power ratings and energy use. Each one has a worked solution and a mark scheme showing where the marks go.