Question

A discharge of 1 cumec is flowing in a rectangular channel one meter wide at a depth of 20 cm. The bed slope of the channel is?

• A. steep
• B. mild
• C. adverse
• D. critical

Answer 1

The correct option is A steep

$y_c={\left(\frac{q^2}{g}\right)}^{1/3}$

$q=\frac{1}{1}=1m^3/s/m$

$\therefore y_c={\left(\frac{1^2}{9.81}\right)}^{1/3}=0.467m$

$y_n=0.2m$

Since $y_c>y_n$ hence steep slope.