• # question_answer                           A single-stage impulse 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) $45{}^\circ$m/s                     D) 900 m/s

$u=\frac{\pi DN}{60}=\frac{\pi \times 1.2\times 300}{60}=188.5\,\,\text{m/s}$ $\rho =\frac{u}{{{v}_{a\,1}}}$ ${{v}_{a\,1}}=\frac{188.5}{0.42}=4488=45{}^\circ \text{m/s}$