Fluid Kinematics MCQ with answer and solution

Concept

Definition of compressible fluid flow

Formula

NONE

Step-by-step solution

1. Fluid flow classification depends on how fluid density and velocity vary across a flow region. 2. If the density of a fluid changes from point to point, the fluid undergoes volume variations under pressure. 3. Flow in which fluid density varies from point to point is called compressible flow. Answer: D

Explanation

A flow is classified as compressible when the density of the fluid varies throughout the flow field due to changes in pressure or temperature. In contrast, incompressible flow assumes fluid density remains constant across all points. Gas flows at high speeds often exhibit compressible behavior due to varying density.

Why the other options are wrong

A) Steady flow occurs when fluid parameters at any point do not change with time. B) Unsteady flow occurs when fluid parameters at a given location change with time. C) Non-uniform flow occurs when velocity varies between different points along a flow path.

Shortcut

Variable density from point to point defines Compressible flow.

Common mistake

Confusing density variation in space (compressible flow) with velocity variation in space (non-uniform flow).