Top 250+ Solved Refrigeration and Air conditioning MCQ Questions Answer
Q. The condition of refrigerant before and after the condenser in a vapour compression cycle is
a. Wet vapour, wet vapour
b. Dry saturated, wet vapour
c. Dry saturated, dry saturated
d. Liquid, liquid
e. Dry saturated, saturated liquid
Q. The COP of a reversed Carnot cycle is 5. The ratio of highest absolute temperature to the lowest absolute temperature
a. 0.8
b. 1.2
c. 0.2
d. 1.25
e. 5
Q. In case the relative humidity of atmospheric air is 100% the rate of evaporation of water will be
a. Half the water already air
b. Very high
c. Zero
d. Slow
e. Half the water already air
Q. In which of the following plants secondary refrigerant is used?
a. Domestic refrigerator
b. Room air conditioner
c. Deep freezer
d. Ice plant
e. None of the above
Q. If the suction pressure of a refrigeration compressor is too high, it shows
a. Lack of refrigerant on cycle
b. Excessive load and evaporator
c. Negligible load on evaporator
d. Any of above
e. None of the above
Q. The crankcase explosion of a refrigeration compressor
a. Occurs due to ignition of vapours in compressor crank case
b. Occurs when load is too high
c. Means breakdown in compression
d. Occurs between piston and cylinder heads
e. Means ignition of refrigeration due to high temperature
Q. A cooling tower cools water
a. Below wet bulb temperature
b. Equal to wet bulb temperature
c. Slightly above wet bulb temperature
d. Wet bulb has no bearing on cooling load performance
e. None of the above
Q. While designing air conditioning system for a theatre the various heat loads are categorized as given below. Which one will give lowest heat load?
a. Lights
b. Neither absorbs nor discards heat
c. Outside temperature in summer
d. Human beings
e. Direct sun
Q. The secondary refrigerant used in milk chilling plants is usually
a. Brine
b. Ammonia solution
c. Glycol
d. Sodium silicate
e. Any of the above
Q. Hydrogen cannot be liquefied at room temperature by the application of pressure, because
a. It is a diatomic molecule
b. It has high viscosity
c. Its critical temperature is lower than the normal room temperature
d. Its thermal conductivity is high
e. It has low density
Q. The condension of moisture contained in air will take place at
a. Any where between dry bulb temperature and wet bulb temperature
b. Dew point temperature
c. Dry bulb temperature
d. Wet bulb temperature
e. Saturation temperature
Q. If a discharge pressure of a refrigeration compressor is too high, it shows there is (are)
a. Too little or too warm condenser water
b. Fouled tubes in shell and tube condenser
c. Improper operations of evaporator condenser
d. Overcharge of refrigerant
e. Any of the above
Q. The statement that molecular weight of all gases occupy the same volume at NTP is known as
a. First law of thermodynamics
b. Joules law
c. Charle's law
d. Avogadro's law
e. Dalton's law
Q. The condition of refrigerant before and after the expansion or throttle valve in a vapour compression system is
a. Wet vapour, very wet vapour
b. Wet vapour, dry vapour
c. High pressure saturated liquid, very wet vapour
d. Very wet vapour, high pressure, saturated liquid
e. None of the above
Q. The function of desuperheating coil in a condenser is
a. To remove heat from condenser
b. To improve performance of a condenser
c. To discharge the heat exchanged in condenser to the surroundings
d. To remove the heat of superheat of the refrigerant before it enters the condenser
e. None of the above