GATE Exam Questions - Engineering

Q1:

At the same mean velocity, the ratio of head loss per unit length for a sewer pipe flowing full to that for the same pipe flowing half full would be :

A 2.0

B 1.63

C 1.00

D 0.61

ANS:B - 1.63

hl = fL(16Q^2)/2g(3.14^2)Xd^5 in terms of discharge.
for half flow it will be 8Q^2,
So, it will be 16/8 =2,
A is the correct answer.