Question

Flow in a pipe is laminar if Reynolds number is ____

• A. Less than \(2000\)
• B. Between \(4000\) and \(6000\)
• C. Between \(2000\) and \(4000\)
• D. Above \(6000\)

Hint:

Pipe flow classification: \[ \boxed{ \begin{aligned} Re\lt 2000 &\rightarrow \text{Laminar}\\ 2000\lt Re\lt 4000 &\rightarrow \text{Transition}\\ Re\gt 4000 &\rightarrow \text{Turbulent} \end{aligned} } \]

Answer 1

The Correct Option is A

Step 1: Recall Reynolds number classification. For flow through circular pipes, \[ Re=\frac{\rho VD}{\mu} \] is used to classify the type of flow.

Step 2: Identify the laminar range. \[ \boxed{ Re\lt 2000 } \] indicates laminar flow. Hence, \[ \boxed{(A)} \] is the correct answer.