SSC JE Civil Engineering 30-Oct-2020 Shift 2 Paper

Explanation:
Flow ratio
The flow ratio of Francis turbine is defined as the ratio of the velocity of flow at the inlet to the theoretical jet velocity.
$\mathrm{Flow}\mathrm{Ratio}=\frac{{{\mathrm{V}}_{\mathrm{f}}^{}}_1^{}}{\sqrt{\overline{2}\overline{\mathrm{g}}\overline{\mathrm{H}}}}$
In the case of Francis turbine,
Flow ratio varies from 0.15 to 0.3
Speed ratio varies from 0.6 to 0.9
Calculation:
$\mathrm{Flow}\mathrm{Ratio}=\frac{7}{\sqrt{\overline{2}\overline{\times }\overline{10}\overline{\times }\overline{62}}}=0.2$