Q 11-05-010NEETNEET 2021Top questionEasy
Water falls from a height of $60$ m at the rate of $15$ kg/s to operate a turbine. The losses due to frictional force are $10\%$ of the input energy. How much power is generated by the turbine ? ($g = 10\ \text{m/s}^2$)
Answer: (C) $8.1$ kW
Input power:
$$P_{in} = \frac{dm}{dt}gh = 15 \times 10 \times 60 = 9000\ \text{W}$$
After $10\%$ losses:
$$P = 0.9 \times 9000 = 8100\ \text{W} = 8.1\ \text{kW}$$
Solution by Sreeraj P, M.Sc Physics