Question

The diameter of a circular sewer is 0.8m. The desired depth of flow is __________

(a) 2/3 of the circular section of sewer

(b) 1/3 of the circular section of sewer

(c) 1/2 of the circular section of sewer

(d) 1/4 of the circular section of sewer

This question was posed to me during an interview.

Asked question is from Hydraulic Elements of Circular Sewers topic in chapter Hydraulic Design of Sewers of Environmental Engineering

Answer 1

Correct answer is (a) 2/3 of the circular section of sewer

To explain I would say: When the diameter of the sewer is between 0.4m and 0.8m, they are designed to flow at 2/3 depth.