A lamp transfers 25 J of energy from the mains supply each second. Each second, 4 J of energy is transferred usefully by light. What is the efficiency of the lamp as a percentage?
[1]
A
4 %
B
6 %
C
16 %
D
21 %
Markscheme
1.2 Conservation and dissipation of energy Questions
40 exam-style questions on AQA GCSE Physics 1.2 Conservation and dissipation of energy, covering 1.2.1 Energy transfers in a system and 1.2.2 Efficiency. Each one has a worked solution and a mark scheme showing where the marks go.