Laminar Flow MCQ with answer and solution

Concept

Laminar Flow Friction Factor

Formula

f = 64 / Re

Step-by-step solution

Identify the flow as laminar and apply the standard Darcy-Weisbach friction factor formula f = 64/Re.

Explanation

In fully developed laminar flow through a pipe, the friction factor depends only on the Reynolds number and is inversely proportional to it, defined by the Darcy-Weisbach friction factor formula f = 64/Re.

Shortcut

Remember the number 64 for Darcy friction factor in laminar pipe flow (f = 64/Re), or think of "64" as 8 x 8, while 16/Re is the Fanning friction coefficient.

Common mistake

Many students confuse the Darcy-Weisbach friction factor (f = 64/Re) with the Fanning friction coefficient (f' = 16/Re) and mistakenly select Option B.