SSC JE Civil Engineering 30-Oct-2020 Shift 1 Paper

For steady laminar flow, head loss due to friction in a circular pipe is,
hf=

128µ‌QL

πγD4

Head loss due to friction in a circular pipe of diameter D, under laminar flow, is inversely proportional to D4.
Laminar flow through a circular pipe:
Reynold’s number is important in the case of pipe flow.
Re=

inertia force

viscous force

=

ρ‌VD

µ

If Re<2000 for laminar flow
Re>4000 for turbulent flow