Question

A hydraulic jump occurs in a open channel. The depth of flow before jump and after jump are 0.6 m and 1.2 m respectively. the efficiency of jump is ______ %

• A. 87.5

Answer 1

The correct option is A 87.5
Given,
$y_1=0.6m,y_2=1.2m$

Energy loss,
$\Delta E=\frac{(y_2-y_1{)}^3}{4y_1{y}_2}$

$=\frac{(1.2-0.6{)}^3}{4\times 0.6\times 1.2}$

= 0.075 m

$n_{jump}=\frac{E_1-\Delta E}{E_1}$

$=\frac{0.6-0.075}{0.6}(E_1=y_1)$

= 0.875

= 87.5 %