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1.7.1a Energy stores and energy transfers

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Question 53

An engineer is evaluating the performance of an electrical machine. Which expression gives the percentage efficiency of the machine?

A

total power outputtotal power input×100%\frac{\text{total power output}}{\text{total power input}} \times 100\%total power inputtotal power output​×100%

B

useful power outputtotal power input×100%\frac{\text{useful power output}}{\text{total power input}} \times 100\%total power inputuseful power output​×100%

C

wasted power outputtotal power input×100%\frac{\text{wasted power output}}{\text{total power input}} \times 100\%total power inputwasted power output​×100%

D

useful power outputwasted power output×100%\frac{\text{useful power output}}{\text{wasted power output}} \times 100\%wasted power outputuseful power output​×100%

Markscheme

1.7.1a Energy stores and energy transfers Questions

  1. IGCSE
  2. /Physics
  3. /1.7.1a Energy stores and energy transfers

229 exam-style questions on CIE IGCSE Physics 1.7.1a Energy stores and energy transfers. Each one has a worked solution and a mark scheme showing where the marks go.

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