Question

For a pipe of radius, r, flowing half full under the action of gravity, the hydraulic depth is

• A. 0.379r
• B. $\frac{\pi r}{4}$
• C. r
• D. $\frac{r}{2}$

Answer 1

The correct option is B $\frac{\pi r}{4}$

Area,
A=$\frac{\pi r^2}{2}$

Top width,
T = 2r

$therefore,Hydraulicdepth$

$=\frac{A}{T}=\frac{\pi r^2}{2\times 2r}=\frac{\pi r}{4}$