An air compressor has eight stages of equal pressure ratio 1.35. The flow rate through the compressor and its overall efficiency are 50 kg/s and 82% respectively. If the air enters the compressor at a pressure of 1.0 bar and temperature of 313K determine
(i) State of air at the exit of the compressor
(ii) Polytropic or small stage efficiency
(iii) Efficiency of each stage
(iv) Power required to drive the compressor assuming the overall efficiency as 90%.