Question

Which of the following is the expression of  the Manning’s formula?

(a) V = R^1/3 S^1/2/ N

(b) V = R^2/3 S^2/ N

(c) V = R^2/3 S^1/2/ N

(d) V = R^2/3 S^1/2

The question was asked by my school principal while I was bunking the class.

My doubt stems from Hydraulic Formulae topic in chapter Hydraulic Design of Sewers of Environmental Engineering

Answer 1

The correct choice is (c) V = R^2/3 S^1/2/ N

For explanation: The Manning’s formula is given by V = R^2/3 S^1/2/ N where V is the velocity of flow, ‘R’ is the mean hydraulic radius, ‘S’ is the slope of the sewer and ‘N’ is the rugosity coefficient.