SSC JE Mechanical Engineering 27 Sep 2019 Shift 1 Paper

Piston Displacement: The volume swept by the piston during single stroke of the piston working in a cycle.
Or, the volume of cylinder from the top dead centre to the bottom dead centre.
The swept volume VS is the product of the cross-section area of the cylinder and the length travelled by piston.
Cross-section area of cylinder ${\mathit{A}}_{\mathit{C}}=\frac{\mathrm{\pi }{\mathit{D}}^2}{4}$,
Length travelled by piston or stroke length $=\mathit{L}$
Then swept volume ${\mathit{V}}_{\mathit{S}}=\frac{\mathrm{\pi }{\mathit{D}}^2}{4}\times \mathit{L}$
And swept volume per second for $\mathit{K}$ number of cylinders of compressor is given by;
${\mathit{V}}_{\mathit{S}}=\frac{\mathrm{\pi }{\mathit{D}}^2}{4}\times \mathit{L}\times \mathit{n}\times \mathit{K}$
where, $\mathit{n}=$ no. of revolution per sec.