An offshore wind farm generates 12 MW12\text{ MW}12 MW of electrical power, which is transmitted to the mainland grid through a subsea cable with a total resistance of 1.5 Ω.
If the power is transmitted at a potential difference of 15 kV15\text{ kV}15 kV instead of 60 kV60\text{ kV}60 kV, how much additional power is dissipated as thermal energy in the transmission cable?
0.54 MW0.54\text{ MW}0.54 MW
0.90 MW0.90\text{ MW}0.90 MW
1.02 MW1.02\text{ MW}1.02 MW
0.06 MW0.06\text{ MW}0.06 MW
39 exam-style questions on OCR GCSE Physics Powering Earth. Each one has a worked solution and a mark scheme showing where the marks go.