Refrigeration and Air Conditioning

Formation of frost on evaporator in refrigerator ________________? 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…

At lower temperatures and pressures, the latent heat of vaporisation of a refrigerant_________________? A. decreasesB. increases C. remains same D. depends on other factors E. none of the above…

Which of the following is not a desirable property of a refrigerant_________________? A. high triiscibility with oil B. low boiling pointC. good electrical conductor D. large latent heat E. non-inflammable…

Pick up the correct statement about giving up of heat from one medium to other in ammonia absorption system ? A. strong solution to weak solutionB. weak solution to strong solution C. strong solution to ammonia vapour D. ammonia…

If the evaporator temperature of a plant is lowered, keeg the condenser temperature constant, the h.p. of compressor required will be________________? A. sameB. more C. less D. more/less depending on rating E. unpredictable…

Highest pressure encountered in a refrigeration system should be________________? A. critical pressure of refrigerantB. much below critical pressure C. much above critical pressure D. near critical pressure E. there is no such…

A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure of about 67 kg/cm. The refrigerant used is________________? A. AmmoniaB. Carbon dioxide C. Freon D. Brine E.…

Where does the lowest temperature occur in a vapour compression cycle ? A. condenserB. evaporator C. compressor D. expansion valve E. receiver

Mass flow ratio of NH3 in comparison to Freon-12 for same refrigeration load and same temperature limits is of the order of___________________? A. 1 : 1B. 1 : 9 C. 9 : 1 D. 1 : 3 E. 3 : 1

Ammonia is __________________? A. non-toxic B. non-inflammable C. toxic and non-inflammableD. highly toxic and inflammable E. none of the above