Air refrigeration cycle is used in
A
Domestic refrigerators
B
Commercial refrigerators
C
Air conditioning
D
Gas liquefaction
Correct Answer: Gas liquefaction
The processes are used for scientific, industrial and commercial purposes. Many gases can be put into a liquid state at normal atmospheric pressure by simple cooling; a few, such as carbon dioxide, require pressurization as well.At ambient pressure the boiling point of liquefied helium is 4.22 K