REFRIGERATION and AIR CONDITIONING MCQ
1.Nusselt number (NN) is given by
A.NN = hl/k
B.NN = μ cp/k
C.NN = ρ V l /μ
D.NN = V²/t.cp
2.In case of sensible heating of air, the coil efficiency is given by (where B.P.F. = Bypass factor)
A.B.P.F. – 1
B.1 – B. P.F.
C.1/ B.P.F.
D.1 + B.P.F
3.The undesirable property of a refrigerant is
A. Non-toxic
B. Non-flammable
C. Non-explosive
D. High boiling point
4.The desirable property of a refrigerant is
A. Low boiling point
B. High critical temperature
C. High latent heat of vaporization
D. All of these
5.The operating pressure for refrigerating units using R-12 as a refrigerant is
A.2 bar
B.8 bar
C.15 bar
D.30 bar
6.Cooling water is required for following equipment in ammonia absorption plant
A. Condenser
B. Evaporator
C. Absorber
D. Condenser, absorber and separator (rectifier)
7.The coefficient of performance of a domestic refrigerator is ________ as compared to a domestic air-conditioner.
A. Same
B. Less
C. More
D. None of these
8.In aqua ammonia and Lithium bromide water absorption refrigeration systems, the refrigerants are respectively
A. Water and water
B. Water and lithium bromide
C. Ammonia and lithium bromide
D. Ammonia and water
9.In order to cool and dehumidify a stream of moist air, it must be passed over the coil at a temperature
A. Which lies between the dry bulb and wet bulb temperatures of the incoming stream
B. Which lies between the wet bulb and dew point temperatures of the incoming stream
C. Which is lower than the dew point temperature of the incoming stream
D. Of adiabatic saturation of incoming stream
10.During heating and dehumidification process, dry bulb temperature
A. Remains constant
B. Increases
C.Decreases
D. None of these
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