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1.7 Energy, work and power

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Question 399

An electric motor is described as having a very high efficiency.

Which statement must be correct?

A

Most of the input energy is transferred into useful output energy.

B

It requires very little input power to operate.

C

It minimizes the time required to perform work.

D

It generates a large amount of thermal energy as waste.

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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