Q.

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              [2021, 2008]
 

1 7.0 kW  
2 10.2 kW  
3 8.1 kW  
4 12.3 kW  

Ans.

(3)

Given, h=60 m

Now, water falls at the rate of 15 kg is

i.e., mt=15kg/s

g=10m/s2

As loss due to friction is 10%, therefore only 90% of input energy is used to generate power.

   P=ghmt×90100

P=10×60×15×90100=8100WP=8.1kW