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Power and efficiency

Power and efficiency

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Question 5

An electric motor, used to lift a heavy load, has an input energy transfer of 240 000 J240\,000\text{ J}240000 J per minute.

The motor has an efficiency of 0.75.

Use the equation:

Efficiency=Useful output energy transferInput energy transfer \text{Efficiency} = \frac{\text{Useful output energy transfer}}{\text{Input energy transfer}} Efficiency=Input energy transferUseful output energy transfer​

Calculate the useful output energy transfer per minute.

A

4000 J4000\text{ J}4000 J

B

60 000 J60\,000\text{ J}60000 J

C

180 000 J180\,000\text{ J}180000 J

D

320 000 J320\,000\text{ J}320000 J

Markscheme

Power and efficiency Questions

  1. GCSE
  2. /Physics
  3. /Power and efficiency

37 exam-style questions on OCR GCSE Physics Power and efficiency. Each one has a worked solution and a mark scheme showing where the marks go.

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