Question

Water falls from a height of 60 m at the rate of 15 kg/s to operate a turbine. The losses due to frictional forces are 10% of energy. How much power is generated by the turbine ? (g = 10 m/s$^2$)

• A. 12.3 kW
• B. 7.0 kW
• C. 8.1 kW
• D. 10.2 kW

Answer 1

Answer: (C)

8.1 kW

Answer 2

Mass of water falling/second = 15 kg/s
h = 60 m
g= 10 m/s$^2$, loss = 10%

i.e., 90% is used.
Power generated = 15 $\times$ 10 $\times$ 60 $\times$ 0.9
= 8100 W = 8.1 kW.