Note AcademyNote Academy
Start

Physics (AS & A Level) · Oct / Nov 2025 · Paper 14 · Question 18

9702Energy conservation

The total energy supplied to an electric motor is E. Energy Q is wasted and the remaining energy does useful work. What is the efficiency of the motor?

  1. A\frac{Q}{E}
  2. B\left(\frac{Q}{E}\right) - 1
  3. C1 - \left(\frac{Q}{E}\right)
  4. D\frac{(1-Q)}{E}

As printed in the paper

Show the answer

Correct answer: C. 1 - \left(\frac{Q}{E}\right)

Sit this whole paper →More on Energy conservation

Make a free account to save your answers and see your weak topics and ask the AI why a wrong answer is wrong.