Download Aptitude Crack
img not found img not found

UPSC Civil Service Exam Questions - Engineering

Q1:

In steady laminar flow of a liquid through a circular pipe of internal diameter D, carrying a constant discharge, the hydraulic gradient is inversely proportional to

A D

B D2

C D4

D D5

ANS:B - D2

Headloss=32uVL/yD^2.
= 32uQL/yAD^2.
= 32uLQ/yD^2(π/4)D^2.
=128 uLQ/yπD^4.

Therefore, hydraulic gradient=gf/L.
= 128 uQ/yπD^4.
Hf is inversely proportional to D^4.