Top 250+ Solved Refrigeration and Air conditioning MCQ Questions Answer
Q. Dry bulb temperature depends on
a. Humidity of air
b. Water vapour content of air
c. Condition of air
d. All above
e. None of the above
Q. In a psychrometric chart vertical lines indicate
a. Dew point temperature
b. Dry bulb temperature
c. Wet bulb temperature
d. Percentage humidity
e. Relative humidity
Q. In case of completely dry air
a. Total heat is same as latent heat
b. Total heat is same as sensible heat
c. Total heat is sum of sensible heat and latent heat
d. Total heat is sum of sensible heat required for all individual constituents
e. None of the above
Q. When the lower temperature is fixed, the COP of a refrigerating machine can be improved by
a. Operating the machine at higher speeds
c. Raising the higher temperature
d. Lowering the higher temperature
e. None of the above
Q. Water is used as a refrigerant in
a. Vapour absorption cycle
b. Steam jet refrigeration
c. Vapour absorption cycle
d. Cascade system
e. None of the above
Q. During adiabatic saturation process on unsaturated air
a. Dry bulb temperature remains constant
b. Wet bulb temperature remains constant
c. Dew point temperature remains constant
d. Relative humidity remains constant
e. None of the above
Q. In a vapour compression refrigeration cycle, high head pressure is indicated which does not change even when compressor is stopped and allowed to cool. The probable cause may be
a. High refrigerant charge
b. Low refrigerant charge
c. Air in the system
d. High vapour pressure
e. Any of the above
Q. A critical temperature is the temperature
a. Below which gas is always liquefied
b. Above which a gas will never be liquefied
c. Below which a gas does not obey gas laws
d. Above which a gas may explode
e. None of the above
Q. A Salinometer
a. Measure intensity of illumination
b. Measures temperatures in cryogenic regions
c. Measures solar radiation
d. Measures sound level
e. Measures density of brine
Q. In cooling towers the heat is dissipated mainly by
a. Freezing
b. Convection
c. Radiation
d. Conduction
e. Evaporation
Q. Capacity of a domestic refrigerator is in the range
a. 1 to 3 tonnes
b. 7 to 10 tonnes
c. 0.1 to 0.3 tonnes
d. 3 to 5 tonnes
e. 5 to 7 tonnes
Q. If a refrigerator is directly exposed to sun rays
a. It will stop working
b. The refrigerant will leak
c. There will be less cooling effect
d. Frost will be formed on cabinet surface
e. (A) and (B) above
Q. A refrigerating system operates on the reversed Carnot cycle. The higher temperature of the refrigerant in the system is 40?C and the lower is - 15?C. The capacity is to be 10 tons. Neglecting all losses, the coefficient of performance of the system would be
a. 2.67
b. 3.75
c. 9.41
d. 4.69
e. 7.36
Q. As warm air cools, its
a. Relative humidity increases
b. Relative humidity decreases
c. There is no effect on moisture holding capacity
d. Capacity to hold moisture increases
e. Dew point occurs
Q. In a small vapour compression cycle using capillary tubing for expansion, if suddenly uncondensed vapours enter the tubing, the result will be
a. Improved refrigerating capacity
b. Loss in refrigerating capacity
c. Supply of superheated vapour to compressor
d. Choking of drier
e. All of the above