An offshore wind farm generates 12 MW12\text{ MW}12 MW of electrical power to be transmitted to the mainland grid through cables with a total resistance of 5.0 Ω.
The transmission voltage can either be stepped up to 120 kV120\text{ kV}120 kV using a transformer at the wind farm, or transmitted directly at the generator output voltage of 24 kV24\text{ kV}24 kV.
What is the reduction in power lost as thermal energy in the transmission cables when the higher transmission voltage is used instead of the lower voltage?
50 kW50\text{ kW}50 kW
1200 kW1200\text{ kW}1200 kW
1250 kW1250\text{ kW}1250 kW
1150 kW1150\text{ kW}1150 kW
28 exam-style questions on Edexcel IGCSE Physics Mains electricity. Each one has a worked solution and a mark scheme showing where the marks go.