A power station supplies 1200 MW1200\ \text{MW}1200 MW of power to the national grid.
36 MW36\ \text{MW}36 MW of this power is wasted heating the transmission cables.
Calculate the power that reaches the consumers.
Calculate the percentage of the power supplied by the power station that reaches the consumers.
Use the equation: energy transferred=power×time\text{energy transferred} = \text{power} \times \text{time}energy transferred=power×time
Calculate the energy wasted heating the transmission cables in 1 hour.
Give your answer in joules, in standard form.
Explain how transmitting the same power at a higher potential difference would reduce the power wasted in the cables.
16 exam-style questions on OCR GCSE Physics 8.2 Powering Earth, covering 8.2.1 Renewable and non-renewable energy resources, 8.2.2 Patterns and trends in energy use, 8.2.3 The national grid, 8.2.4 Step-up and step-down transformers, 8.2.5 Efficiency of the national grid, 8.2.6 Transformers and power transmission at high voltage, 8.2.7 The UK domestic supply, 8.2.8 Direct and alternating potential difference, 8.2.9 Live, neutral and earth wires, and 8.2.10 Dangers of mains electricity. Each one has a worked solution and a mark scheme showing where the marks go.