Question

A triangular channel having apex angle 90° carries water at critical specific energy of 1.2m. The critical discharge through channel is ______ cumecs.

• A. 2

Answer 1

The correct option is A 2
Given, Apex angle = 90° $\Rightarrow$ m = 1
$E_c$ = 1.2m
For triangular channel,
$E_c$ = 1.25 $y_c$

$\Rightarrow y_c=\left(\frac{1.2}{1.25}\right)=0.96m$

$y_c={\left(\frac{2Q_c^2}{g{m}^2}\right)}^{1/5}$

$0.96={\left(\frac{2Q_c^2}{9.81\times 1}\right)}^{1/5}$

$Q_c=2cumecs$