Top 250+ Solved Refrigeration and Air conditioning MCQ Questions Answer
Q. Clear ice
a. Is pure ice
b. Contains dissolved air
c. Contains dissolved gases
d. Is produced by blowing air during freezing
e. None of the above
Q. Two thermometers are constructed in the same way except that one has a spherical bulb and the other an elongated cylindrical bulb. Which one will respond quickly to temperature change?
a. Spherical bulb thermometer
b. Cylindrical bulb thermometer
c. Both will respond in identical manner
d. Cannot be ascertained on the basis of information provided
e. None of the above
Q. A low wet bulb temperature indicates
a. Very cool air
b. Very low humidity
c. Very low atmospheric temperature
d. (A) and (B) above
e. (A) and (C) above
Q. On a psychrometric chart sensible heating or cooling is represented by
a. A horizontal line
b. A vertical line
c. Inclined line
d. Curved line
e. None of the above
Q. During sensible heating of air
a. Dry bulb temperature increases while enthalpy of moist air decreases
b. 10,000 m height above the surface of earth
c. Both dry bulb temperature as well as enthalpy decrease
d. Both dry bulb temperature as well as enthalpy increase
e. Dry bulb temperature decreases while enthalpy of moist air increases
Q. Air and other non-condensable gases (foul gases) get into a refrigeration system through
a. Decomposition of refrigerant in contact with impurities
b. Breakdown of oil
c. Under vacuum operation or during maintenance work
d. Corrosion
e. Any of the above
Q. The relation between vapour pressure to the enthalpy of vaporisation is expressed in
a. Vander wall's equation
b. Energy equation
c. Maxwell's equation
d. Clausius Clapeyron equation
e. Lewis equation
Q. For a sensible heating the air is passed over a heating coil which may be
a. Heated by electric resistance
b. Heated by passing hot water through the coil
c. Heated by passing steam through the coil
d. Heated by direct solar radiations
e. Heated by any of the above methods
Q. Cryogenics
a. Is same as refrigeration
b. Include heating and cooling of liquids
c. Is a thermodynamic analysis of low temperature systems
d. Is the field of engineering associated with development, production and use of equipment in the range -180?C to absolute zero
e. None of the above
Q. Dew point is
a. The temperature at which ice starts melting in presence of air without external aid
b. Percentage of moisture contained in a sample of air
c. The temperature of water vapour in air starts
d. Partial pressure of water vapour in a sample of air
e. The temperature at which condensation of water vapour in air starts
Q. A refrigerant with lowest freezing point temperature is
a. Ammonia
b. Freon 12
c. Freon 22
d. Carbondioxide
e. Freon 11
Q. A storage tank which receives liquid refrigerant from evaporator and prevents it from flowing into suction line is known as
a. Accumulator
b. Agitator
c. Balancer
d. Condenser
e. None of the above
Q. In a vapour compression refrigeration cycle using ammonia as a refrigerant the temperature of ammonia after compression will be at the range
a. 40?C to 0?C
b. 70?C to - 110?C
c. 0?C to - 15?C
d. ? 15?C to - 40?C
e. 50?C to 40?C
Q. The condition of refrigerant before and after compression in vapour compression cycle is
a. Wet vapour, wet vapour
b. Dry saturated vapour, liquid
c. Dry saturated vapour, superheated vapour
d. Wet vapour, cry saturated vapour
e. Liquid, wet vapour