Refrigeration and Air Conditioning A reversible engine has ideal thermal efficiency of 30%. When it is used as a refrigerating machine with all other conditions unchanged, the coefficient of performance will be 2.33 3.33 1.33 4.33 2.33 3.33 1.33 4.33 ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning A refrigerating system operating on reversed Brayton refrigeration cycle is used for maintaining 250 K. If the temperature at the end of constant pressure cooling is 300 K and rise in the temperature of air in the refrigerator is 50 K, then the net work of compression will be (assume air as working substance with Cp = 1 kJ/kg) 125 kJ/kg 25 kJ/kg 100 kJ/kg 50 kJ/kg 125 kJ/kg 25 kJ/kg 100 kJ/kg 50 kJ/kg ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning If a heat pump cycle operates between the condenser temperature of +27°C and evaporator temperature of -23°C, then the Carnot COP will be 5 0.2 6 1.2 5 0.2 6 1.2 ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning Formation of frost on evaporator in refrigerator Can be avoided by proper design Is immaterial Increases heat transfer rate Results in loss of heat due to poor heat transfer Can be avoided by proper design Is immaterial Increases heat transfer rate Results in loss of heat due to poor heat transfer ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning The sub-cooling in a refrigeration cycle Does not alter C.O.P. None of these Increases C.O.P. Decreases C.O.P. Does not alter C.O.P. None of these Increases C.O.P. Decreases C.O.P. ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning In a refrigerating machine, heat rejected is _________ heat absorbed. None of these Equal to Greater than Less than None of these Equal to Greater than Less than ANSWER DOWNLOAD EXAMIANS APP
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