A household instantaneous electric shower has a power rating of 9.6 kW, whereas an LED desk lamp has a power rating of 8 W.
Explain why the copper conductors in the dedicated cable supplying the electric shower must have a significantly larger cross-sectional area than the copper conductors in the flexible cable of the desk lamp.
10 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.