Laminar Flow MCQ with answer and solution

Concept

Friction factor in laminar pipe flow

Formula

NONE

Step-by-step solution

1. Theoretically, the friction factor for laminar pipe flow is given by f = 64/Re, which is inversely proportional to the Reynolds number. Answer: A

Explanation

For fully developed laminar flow in a circular pipe, Darcy's friction factor is calculated as 64 divided by the Reynolds number. This mathematical relationship shows that the friction factor is inversely proportional to the Reynolds number. Thus, option A is correct.

Why the other options are wrong

B) Froude number relates inertial forces to gravitational forces in open channel flow. D) Prandtl number represents the ratio of momentum diffusivity to thermal diffusivity.

Shortcut

For laminar flow in pipes, friction factor f = 64/Re, which is inversely proportional to Reynolds number.

Common mistake

Confusing laminar flow friction factor (64/Re) with turbulent flow friction factor or other dimensionless numbers.