Refrigeration and Air Conditioning The relative coefficient of performance is equal to (Theoretical C.O.P.)/ (Actual C.O.P.) None of these (Actual C.O.P.) /(Theoretical C.O.P.) (Actual C.O.P.) × (Theoretical C.O.P.) (Theoretical C.O.P.)/ (Actual C.O.P.) None of these (Actual C.O.P.) /(Theoretical C.O.P.) (Actual C.O.P.) × (Theoretical C.O.P.) ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning Nusselt number (NN) is given by NN = ρ V l /μ NN = V²/t.cp NN = hl/k NN = μ cp/k NN = ρ V l /μ NN = V²/t.cp NN = hl/k NN = μ cp/k ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning The comfort conditions in air conditioning are at (where DBT = Dry bulb temperature, and RH = Relative humidity) 22°C DBT and 60% RH 20°C DBT and 80% RH 25°C DBT and 40% RH 25°C DBT and 100% RH 22°C DBT and 60% RH 20°C DBT and 80% RH 25°C DBT and 40% RH 25°C DBT and 100% RH ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphere is high, then Bigger cabinet should be used Perfectly tight vapour seal should be used Smaller cabinet should be used Refrigerant with lower evaporation temperature should be used Bigger cabinet should be used Perfectly tight vapour seal should be used Smaller cabinet should be used Refrigerant with lower evaporation temperature should be used 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) 100 kJ/kg 25 kJ/kg 50 kJ/kg 125 kJ/kg 100 kJ/kg 25 kJ/kg 50 kJ/kg 125 kJ/kg ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning When the lower temperature of a refrigerating machine is fixed, then the coefficient of performance can be improved by Raising the higher temperature Lowering the higher temperature Operating the machine at lower speeds Operating the machine at higher speeds Raising the higher temperature Lowering the higher temperature Operating the machine at lower speeds Operating the machine at higher speeds ANSWER DOWNLOAD EXAMIANS APP
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