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31. 1 m of air at atmospheric condition weighs approximately__________________?

A. 0.5 kg
B. 1.0 kg
C. 1.3 kg
D. 2.2 kg
E. 3.2 kg

32. Free air is the air at________________?

A. atmospheric conditions at any specific location
B. 20°C and 1 kg/cm2 and relative humidity of 36%
C. 0°C and standard atmospheric conditions
D. 15°C and 1 kg/cm2
E. 25°C, 1 kg/cm2 and relative humidity of 50%.

33. The capacity of a compressor is 5 m /mih. 5 m /min refers to_______________?

A. standard air
B. free air
C. compressed air
D. compressed air at delivery pressure
E. air sucked

34. Maximum work is done in compressing air when the compression is_________________?

A. isothermal
C. polytropic
D. any one of the above
E. none of the above

35. Standard air is the air at_____________________?

A. atmospheric conditions at any specific location
B. 20°C and 1 kg/cm2 and relative humidity 36%
C. 0°C and standard atmospheric conditions
D. 15°C and 1 kg/cm2
E. 25°C, 1 kg/cm2 and RH of 60%.

36. The compressor capacity with decrease in suction temperature_________________?

A. increases
B. decreases
C. remains unaffected
D. may increase or decrease depending on compressor capacity
E. increases upto certain limit and then decreases

37. Inter cooling in compressors__________________?

A. cools the delivered air
B. results in saving of power in compressing a given volume to given pressure
C. is the standard practice for big compressors
D. enables compression in two stages
E. prevents compressor jacket running very hot

38. Isothermal compression though most efficient, but is not -practicable because_________________?

A. ityrequires very big cylinder
B. it does not increase pressure much
C. it is impossible in practice
D. compressor has to run at very slow speed to achieve it
E. it requires cylinder to be placed in water

39. What will be the volume of air at 327°C if its volume at 27°C is 1.5 m3/mt ?

A. 3 m3/mt
B. 1.5 m3/mt
C. 18 m3/mt
D. 6 m3/mt
E. 0.75 m3/mt

40. An ideal air compressor cycle without clearance on p-v diagram can be represented by following processes________________?

A. one adiabatic, two isobaric, and one constant volume
B. two adiabatic and two isobaric
C. two adiabatic, one isobaric and one constant volume
D. one adiabatic, one isobaric and two constant volume
E. two isobaric, two adiabatic and one constant volume