Physics (AS & A Level) · Oct / Nov 2016 · Paper 13 · Question 17

A hydroelectric power station uses the gravitational potential energy of water to generate electrical energy. In one particular power station, the mass of water flowing per unit time is 1.5 × 10^5 kg s^–1. The water falls through a height of 120 m. The electrical power generated is 100 MW. What is the efficiency of the power station?

1. A5.6%
2. B43%
3. C57%
4. D68%

As printed in the paper