An electric motor is given a total energy of $E$. A quantity of energy, $Q$, is wasted, while the rest is used for useful work. What is the efficiency of the motor?
- A$\frac{Q}{E}$
- B$\frac{Q}{E} - 1$
- C$1 - \left(\frac{Q}{E}\right)$
- D$\frac{1 - Q}{E}$
Physics 9702 · AS & A Level · Energy conservation