A single-stage impulse turbine with a diameter of 120 cm runs at 3000 rpm. If the blade speed ratio is 0.42, then, the inlet velocity of steam will be
- A. 79 m/s
- B. 188 m/s
- C. 450 m/s
- D. 900 m/s
Answer: C. 450 m/s
Explanation: Blade speed $u = \frac{\pi D N}{60} \approx 188.5$ m/s. Inlet velocity $V = u / 0.42 \approx 448.8$ m/s.