The document contains 4 questions related to thermodynamics and heat engines. Question 1 defines the formula for volumetric efficiency of a single-stage compressor. Question 2 calculates specifications of a single-stage air compressor like bore, stroke, volumetric efficiency, indicated power, and isothermal efficiency. Question 3 asks to explain the working of an intercooler with a P-V diagram. Question 4 calculates power required, free air delivery, thermal efficiency, and heat transferred in the intercooler for a two-stage compressor with intercooling.