SSC JE Civil Engineering 23-Sep-2019 Shift 2 Solved Paper

For most economical section using chezy's formula depth of flow for maximum discharge through circuler channel of :
d = OD – OC = R – R cos θ
= R[1 – cos θ] = R[1 – cos 154°]
= R[1 – cos(180 – 26°)]
= R[1 + cos 26°] = 1.898 R