Topic: Fluid Machinery
An impulse turbine produces 125 hp under a head of 25 meters. By what percentage should the speed be increased for a head of 100 metres
- A. 25%
- B. 50%
- C. 75%
- D. 100%
Answer: D. 100%
Explanation: Unit speed of turbine is N1/$\sqrt{H1}$ = N2/$\sqrt{H2}$. So, N1/$\sqrt{25}$ = N2/$\sqrt{100}$, meaning N2 = 2*N1. The speed should be increased by 100%.