SSC JE Mechanical Engineering 2018 Set 5 Paper

The continuity equation in fluid flow states that the net rate of inflow into small volume must be zero.
The principle of mass conservation for a steady, one-dimensional flow, with one inlet and one outlet.
$\mathit{Q}={\mathit{A}}_1{\mathit{V}}_1={\mathit{A}}_2{\mathit{V}}_2$
This equation is called the continuity equation for steady one-dimensional flow.
For a steady flow through a control volume with many inlets and outlets, the net mass flow must be zero, where inflows are negative and outflows are positive.