The inter-cooler pressure, for minimum work required, for a two stage reciprocating air compressor, is given by (where p1 = Intake pressure of air, p2 = Inter-cooler pressure and p3 = Delivery pressure of air)

Answer: Option C

The inter-cooler pressure, for minimum work required, for a two stage reciprocating air compressor, is given by $${\text{p}}_2=\sqrt{{\text{p}}_1\times {\text{p}}_2}.$$
Where p₁ = Intake pressure of air, p₂ = Inter-cooler pressure and p₃ = Delivery pressure of air.