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

Solution
Coefficient of Velocity(${\mathrm{C}}_{\mathrm{V}}$ ) is defined as the ratio between the actual velocity of a jet of liquid at vena-contracta and t he theoretical velocity of the jet.
${\mathit{C}}_{\mathrm{V}}=\frac{\mathrm{V}}{\sqrt{2\mathrm{gH}}}$
Co-efficient of contraction( ${\mathrm{C}}_{\mathrm{c}}$ ) is defined as the ratio of the area of the jet at vena-contracta to the area of the orifice.
${\mathrm{C}}_{\mathrm{c}}=\frac{{\mathrm{a}}_{\mathrm{c}}}{\mathrm{a}}$
Co-efficient of Discharge ( ${\mathrm{C}}_{\mathrm{d}}$ ) is defined as the ratio of the actual discharge from an orifice to the theoretical discharge from the orifice.
By the relation
${\mathrm{C}}_{\mathrm{d}}={\mathrm{C}}_{\mathrm{c}}\times {\mathrm{C}}_{\mathrm{v}}$