85. The leaks in a refrigeration system using ammonia are detected by
A.Halide torch which on, detection produces greenish flame lighting
B.Sulphur sticks which on detection give white smoke
C.Using regents
D.Smelling
86. One of the purposes of sub-cooling the liquid refrigerant is to
A.Reduce compressor overheating
B.Reduce compressor discharge temperature increase cooling effect
C.(d) ensure that only liquid and not the vapour enters the expansion (throttling) valve
D.(e) none of the above.
87. Which of the following is not a desirable property of a refrigerant
A.High Miscibility with oil
B.Low boiling point
C.Good electrical conductor
D.Large latent heat
88. Cooling water is required for following equipment in ammonia absorption plant
A.Condenser
B.Condenser, absorber and separator (rectifier).
C.Absorber
D.Condenser and absorber
89. When two refrigerants are mixed in the proper proportions, the mixture forms a third refrigerant called
A.Synthetic refrigerant
B.An azeotrope.
C.High pressure refrigerant
D.Auxiliary refrigerant
90. The condenser and evaporator tubes in a Freon refrigeration plant are made of
A.Steel
B.Copper
C.Brass
D.Aluminium
91. The electrolux refrigerator works on
A.Electro magnetic principle
B.Absorption refrigeration system.
C.Vapour compression system
D.Vortex tube system
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