Question

In water-turbine system, water falls from 20 m at the rate of $10kg{s}^{-1}$. If the losses due to friction are 20%, then power generated by the turbines is :

(take g=$10m/s^2$)

• A. 4 kW
• B. 3.6 kW
• C. 1.6 kW
• D. 2.6 kW

Answer 1

Answer: (C)

1.6 kW

Given,

$\frac{m}{t}=10kg/s$

$h=20m$

$g=10m/s^2$

Due to friction, $20$% input power loss, and only $80$% input power used to generated output,

$P_0=gh\frac{m}{t}\times \frac{80}{100}$

$P_0=10\times 10\times 20\times 0.8$

$P_0=1.6kW$

The correct option is C.