Question

For a hydraulically efficient rectangular channel of bed width 5 m, the hydraulic radius is equal to

• A. 2.5 m
• B. 2 m
• C. 5 m
• D. 1.25 m

Answer 1

The correct option is D 1.25 m

For the most efficient rectangular channel,

$Hydraulicradius=\frac{y}{2}$

$Depth,y=\frac{B}{2}$

$\therefore R=\frac{y}{2}=\left(\frac{B/2}{2}\right)=\frac{B}{4}=\frac{5}{4}=1.25m$