9- Choose the correct answer: 1. In a closed or dense air refrigeration cycle, the operating pressure ratio can be reduced, which results in coefficient of performance. (a) lower (b) higher 2. The efficiency of Carnot heat engine is 80%. The C.O.P. of a refrigerator operating on the reversed Carnot cycle is equal to (a) 0.25 (b) 0.40 (c) 0.60 (d) 0.80 3- In a refrigerating machine, if the lower temperature is fixed, then the C.O.P. of the machine can be increased by (a) increasing the higher temperature (c) operating the machine at a lower speed 6- 4. The highest temperature during the cycle, in a vapour compression refrigeration system, occurs after (a) compression (b) condensation (d) evaporation (c) expansion (b) decreasing the higher temperature (d) operating the machine at a higher speed 5- A system with multiple evaporators at different temperatures with compound compression will (a) increase the power requirements (b) reduce the power requirements (c) neither increase nor reduce the power requirements A rectifier is fitted in an ammonia absorption plant to (a) superbeat ammonia vapour (b) remove the unwanted water vapour by heating the vapour mixture (c) remove the unwanted water vapour by cooling the vapour mixture (d) remove the unwanted water vapour by cooling the vapour mixture and condensing the water vapour (a) dry bulb depression (e) dew point depression 7. The difference between dry bulb temperature and wet bulb temperature, is called (b) wet bulb depression (d) degree of saturation 8. The difference between dry bulb temperature and wet bulb temperature, is called (a) dry bulb depression (c) dew point depression (b) wet bulb depression degree of saturation (d) 10 The temperature of air recorded by a thermometer, when it is not effected by the moisture present in it, is called (a) wet bulb temperature (c) dew point temperature 10- The effective temperature .........with decrease in relative humidity at the same dry bulb temperature. (a) decreases (b) increases Page 201 24 (b) dry bulb temperature (f) none of these CamScanner

9- Choose the correct answer: 1. In a closed or dense air refrigeration cycle, the operating pressure ratio can be reduced, which results in coefficient of performance. (a) lower (b) higher 2. The efficiency of Carnot heat engine is 80%. The C.O.P. of a refrigerator operating on the reversed Carnot cycle is equal to (a) 0.25 (b) 0.40 (c) 0.60 (d) 0.80 3- In a refrigerating machine, if the lower temperature is fixed, then the C.O.P. of the machine can be increased by (a) increasing the higher temperature (c) operating the machine at a lower speed 6- 4. The highest temperature during the cycle, in a vapour compression refrigeration system, occurs after (a) compression (b) condensation (d) evaporation (c) expansion (b) decreasing the higher temperature (d) operating the machine at a higher speed 5- A system with multiple evaporators at different temperatures with compound compression will (a) increase the power requirements (b) reduce the power requirements (c) neither increase nor reduce the power requirements A rectifier is fitted in an ammonia absorption plant to (a) superbeat ammonia vapour (b) remove the unwanted water vapour by heating the vapour mixture (c) remove the unwanted water vapour by cooling the vapour mixture (d) remove the unwanted water vapour by cooling the vapour mixture and condensing the water vapour (a) dry bulb depression (e) dew point depression 7. The difference between dry bulb temperature and wet bulb temperature, is called (b) wet bulb depression (d) degree of saturation 8. The difference between dry bulb temperature and wet bulb temperature, is called (a) dry bulb depression (c) dew point depression (b) wet bulb depression degree of saturation (d) 10 The temperature of air recorded by a thermometer, when it is not effected by the moisture present in it, is called (a) wet bulb temperature (c) dew point temperature 10- The effective temperature .........with decrease in relative humidity at the same dry bulb temperature. (a) decreases (b) increases Page 201 24 (b) dry bulb temperature (f) none of these CamScanner

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter8: Natural Convection

Section: Chapter Questions

Problem 8.46P

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