A power station has an efficiency of 38%. Its useful output power is 760 MW760\ \text{MW}760 MW.
How much power is wasted by the power station?
2000 MW2000\ \text{MW}2000 MW
1240 MW1240\ \text{MW}1240 MW
471 MW471\ \text{MW}471 MW
289 MW289\ \text{MW}289 MW
50 exam-style questions on OCR GCSE Physics 7.2 Power and efficiency, covering 7.2.1 Dissipation of energy, 7.2.2 Energy transfers in domestic devices, 7.2.3 Power ratings of domestic appliances, 7.2.4 Efficiency of energy transfers, 7.2.5 Ways to increase efficiency, 7.2.6 Reducing unwanted energy transfers, and 7.2.7 Thermal conductivity and the cooling of buildings. Each one has a worked solution and a mark scheme showing where the marks go.