Work Energy and Power - Result Question 40
43. 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 energy. How much power is generated by the turbine? [2008] ( $g=10 m / s^{2}$ )
(a) $8.1 kW$
(b) $10.2 kW$
(c) $12.3 kW$
(d) $7.0 kW$
Show Answer
Answer:
Correct Answer: 43. (a)
Solution:
- (a) Given, $h=60 m, g=10 ms^{-2}$,
Rate of flow of water $=15 kg / s$
$\therefore$ Power of the falling water
$=15 kgs^{-1} \times 10 ms^{-2} \times 60 m=9000$ watt
Loss in energy due to friction
$=9000 \times \frac{10}{100}=900$ watt.
$\therefore$ Power generated by the turbine
$=(9000-900)$ watt $=8100$ watt $=8.1 kW$
