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1.7 Energy, work and power

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Question 412

Which statement about efficiency is correct?

A

Efficiency is measured in joules.

B

Efficiency is equal to the ratio of useful energy output to total energy input.

C

Efficiency can be greater than 100% in a closed system.

D

Efficiency is the rate at which energy is transferred.

Markscheme

1.7 Energy, work and power Questions

  1. IGCSE
  2. /Physics
  3. /1.7 Energy, work and power

533 exam-style questions on CIE IGCSE Physics 1.7 Energy, work and power, covering 1.7.1a Energy stores and energy transfers, 1.7.1b Conservation of energy, 1.7.1c Kinetic and gravitational potential energy, 1.7.2 Work done, 1.7.3 Energy resources, 1.7.3a Energy resources and electricity generation, 1.7.3b Nuclear fusion as an energy source, 1.7.3c Efficiency of energy transfer, and 1.7.4 Power. Each one has a worked solution and a mark scheme showing where the marks go.

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