ANS:C - relates mass rate of flow along a stream line

The continuity equation is a fundamental principle in fluid mechanics that relates to the conservation of mass. It states that the mass flow rate is constant within an incompressible fluid flowing through a pipe or conduit of varying cross-sectional area. Mathematically, the continuity equation is expressed as: Mass flow rate = ρAV Where:

• ρ is the fluid density,
• A is the cross-sectional area of the pipe or conduit, and
• V is the fluid velocity.

Therefore, the correct statement about the continuity equation is:

• Relates mass rate of flow along a streamline.

This equation ensures that mass is conserved within the fluid flow and that the rate at which mass enters one section of the flow equals the rate at which it exits. It's a crucial principle for understanding and analyzing fluid flow in various engineering and scientific applications.