Refrigeration and Air Conditioning When the lower temperature of a refrigerating machine is fixed, then the coefficient of performance can be improved by Lowering the higher temperature Raising the higher temperature Operating the machine at lower speeds Operating the machine at higher speeds Lowering the higher temperature Raising the higher temperature Operating the machine at lower speeds Operating the machine at higher speeds 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 25°C DBT and 100% RH 20°C DBT and 80% RH 25°C DBT and 40% RH 22°C DBT and 60% RH 25°C DBT and 100% RH 20°C DBT and 80% RH 25°C DBT and 40% RH ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning Moisture should be removed from refrigerants to avoid Restriction to refrigerant flow Corrosion of steel plates Freezing at the expansion valve All of these Restriction to refrigerant flow Corrosion of steel plates Freezing at the expansion valve All of these ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning The wet bulb temperature during sensible heating of air Decreases Increases Remains constant None of these Decreases Increases Remains constant None of these ANSWER DOWNLOAD EXAMIANS APP
Refrigeration and Air Conditioning The pressure at the outlet of a refrigerant compressor is called Critical pressure Back pressure Discharge pressure Suction pressure Critical pressure Back pressure Discharge pressure Suction pressure 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) 25 kJ/kg 50 kJ/kg 125 kJ/kg 100 kJ/kg 25 kJ/kg 50 kJ/kg 125 kJ/kg 100 kJ/kg ANSWER DOWNLOAD EXAMIANS APP