A theatrical spotlight has a power rating of 1.5 kW. It is switched on for 4.0 min, and 20% of the electrical energy it receives is transferred by light.
How much energy does the spotlight transfer by light in this time?
288 kJ288\ \mathrm{kJ}288 kJ
1.2 kJ1.2\ \mathrm{kJ}1.2 kJ
360 kJ360\ \mathrm{kJ}360 kJ
72 kJ72\ \mathrm{kJ}72 kJ
81 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.