• # question_answer For discharge 'Q' the specific speed of a pump is$'{{N}_{s}}'.$ For half discharge with the same head, the specific speed will be: A) ${{N}_{s}}$                           B) $\sqrt{2}{{N}_{s}}$C) $\frac{{{N}_{s}}}{\sqrt{2}}{{N}_{s}}$                       D) $2{{N}_{s}}.$

For a pump, ${{N}_{s}}=\frac{N\sqrt{Q}}{{{H}^{3/4}}}$ ${{N}_{s}}\propto \sqrt{Q}$ $\frac{{{N}_{s2}}}{{{N}_{s1}}}=\frac{\frac{\sqrt{Q}}{2}}{Q}$ ${{N}_{s2}}={{N}_{s2}}\frac{{{N}_{s}}}{\sqrt{2}}$