Question

A rectangular channel carries a uniform flow with a Froude number of 2.83. The ratio of critical depth to normal depth of this flow is:

• A. 4.75
• B. 1.68
• C. 2.00
• D. 2.83

Answer 1

The correct option is C 2.00

$F_r=2.83=\frac{v}{\sqrt{g{y}_n}}=\frac{q}{y_n\sqrt{g{y}_n}}[\therefore q=v{y}_n]\Rightarrow (2.83{)}^2=\frac{\left(q^2/g\right)}{y_n^3}=\frac{y_c^3}{y_n^3}\Rightarrow \frac{y_c}{y_n}=(2.83{)}^{2/3}=2$