Refrigeration and Air Conditioning

A. lithium bromide used in vapour absorption cycle is nonvolatile
B. lithium bromide plant can’t operate below 0°C
C. a separator is used in lithium bromide plant to remove the unwanted water vapour by condensing
D. concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator
E. weak solution in liquid heat exchanger gives up heat to the strong solution

A. Temperature of medium being cooled must be below that of the evaporator
B. Refrigerant leaves the condenser as liquid
C. All solar thermally operated absorption systems are capable only of intermittent operation
D. frost on evaporator reduces heat transfer
E. refrigerant is circulated in a refrigeration system to transfer heat

A. A refrigerant should have low latent heat
B. If operating temperature of system is low, then refrigerant with low boiling point should be used
C. Precooling and subcooling bf refrigerant are same
D. Superheat and sensible heat of a. refrigerant are same
E. Refrigerant is inside the lubes in case of a direct-expansion chiller

A. liquid
B. sub-cooled liquid
C. saturated liquid
D. wet vapour
E. dry vapour

A. Freon-11
B. Freon-22
C. C02
D. S02
E. ammonia

A. near critical temperature of refrigerant
B. above critical temperature
C. at critica. temperature
D. much below critical temperature
E. could be anywhere

A. reduce compressor overheating
B. reduce compressor discharge temperature
C. increase cooling effect
D. ensure that only liquid and not the vapour enters the expansion (throttling) valve
E. none of the above

A. more
B. less
C. same
D. more for small capacity and less for high capacity
E. less for small capacity and more for high capacity

A. results in loss of heat due to poor heat transfer
B. increases heat transfer rate
C. is immaterial
D. can be avoided by proper design
E. decreases compressor power

A. decreases
B. increases
C. remains same
D. depends on other factors
E. none of the above