less power requirement

better mechanical balance

less loss of air due to leakage past the cylinder

lower volumetric efficiency.

pressure coefficient

work coefficient

polytropic reaction

slip factor

isentropic compression

isothermal compression

polytropic compression

any one of the above

centrifugal

reciprocating

axial

screw

work done in first stage should be more

work done in subsequent stages should increase

work done in subsequent stages should decrease

work done in all stages should be equal