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3.2 Dissipation and efficiency

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Question 48
H

A motor initially receives 600 J and transfers 360 J usefully per operation.

After a modification, the input energy decreases by 20% and the useful energy output decreases by 10%.

Which gives the new efficiency and the change in wasted energy?

[1]
A

efficiency 67.5%67.5\%67.5%; waste decreases by 84 J84\ \mathrm{J}84 J

B

efficiency 54.0%54.0\%54.0%; waste decreases by 84 J84\ \mathrm{J}84 J

C

efficiency 67.5%67.5\%67.5%; waste decreases by 156 J156\ \mathrm{J}156 J

D

efficiency 54.0%54.0\%54.0%; waste decreases by 156 J156\ \mathrm{J}156 J

Markscheme

3.2 Dissipation and efficiency Questions

  1. GCSE
  2. /Physics
  3. /3.2 Dissipation and efficiency

100 exam-style questions on Edexcel GCSE Physics 3.2 Dissipation and efficiency, covering 3.2.1 Dissipation of energy, 3.2.2 Reducing unwanted energy transfers, 3.2.3 Efficiency, and 3.2.4 Increasing efficiency. Each one has a worked solution and a mark scheme showing where the marks go.

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