When the lower temperature of a refrigerating machine is fixed, then the coefficient of performance can be improved by Operating the machine at higher speeds Operating the machine at lower speeds Lowering the higher temperature Raising the higher temperature TRUE ANSWER : ? YOUR ANSWER : ?
The bypass factor, in case of sensible cooling of air, is given by (where td₁ = Dry bulb temperature of air entering the cooling coil, td₂ = Dry bulb temperature of air leaving the cooling coil, and td₃ = Dry bulb temperature of the cooling coil) (td₃ -td₂)/( td₁ -td₃) (td₃ -td₁)/( td₂ -td₃) (td₂ -td₃)/( td₁ -td₃) (td₁ -td₃)/( td₂ -td₃) TRUE ANSWER : ? YOUR ANSWER : ?
The atmospheric air at dry bulb temperature of 15°C enters a heating coil maintained at 40°C. The air leaves the heating coil at 25°C. The bypass factor of the heating coil is 0.6 0.4 0.376 0.67 TRUE ANSWER : ? YOUR ANSWER : ?
Under cooling in a refrigeration cycle Decreases C.O.P Increases C.O.P Other factors decide C.O.P O.P remains unaltered TRUE ANSWER : ? YOUR ANSWER : ?
At lower temperatures and pressures, the latent heat of vaporisation of a refrigerant remains same increases depends on other factors decreases TRUE ANSWER : ? YOUR ANSWER : ?
A refrigerant with the highest critical pressure is R-12 R-22 Ammonia R-11 TRUE ANSWER : ? YOUR ANSWER : ?
The specific humidity during humidification process Decreases None of these Increases Remains constant TRUE ANSWER : ? YOUR ANSWER : ?
The relative humidity is defined as The ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure The mass of water vapour present in 1 m3 of dry air The ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure The mass of water vapour present in 1 kg of dry air TRUE ANSWER : ? YOUR ANSWER : ?
The wet bulb temperature during sensible cooling of air Remains constant None of these Increases Decreases TRUE ANSWER : ? YOUR ANSWER : ?
A refrigerant compressor is used to Circulate the refrigerant through the refrigerating system Raise the temperature of the refrigerant Raise the pressure of the refrigerant All of these TRUE ANSWER : ? YOUR ANSWER : ?