Questions on Refrigeration and Air conditioning
Questions on Refrigeration and Air conditioning
1-COP of refrigeration is always ___ one.
(A) Equal to
(B) Less than
(C) Greater than
(D) None of the above
2-Commonly used refrigerant in a domestic vapor compression refrigerator is
(A) CO2
(B) Freon-12
(C) Ammonia
(D) SO2
3-The expansion device used in domestic refrigerator:
(A) Capillary tube
(B) Float valve
(C) Hand operated expansion valve
(D) Automatic expansion valve
4-Which of the following is highly toxic and flammable refrigerant?
(A) Carbon di-oxide
(B) Ammonia
(C) Air
(D) R-12
5-When heat is absorbed by a gas, change in entropy is considered to be:
(A) Positive
(B) Zero
(C) Negative
(D) One
6-Which of the following is the azeotrope refrigerant?
(A) R-11
(B) R-40
(C) R-114
(D) R-502
7-The refrigerant commonly used in vapor absorption system is:
(A) Water
(B) Freon-12
(C) SO2
(D) Aqua-ammonia
8-In summer Air conditioning, the air is:
(A) Cooled and humidified
(B) Heated and humidified
(C) Cooled and dehumidified
(D) Heated and dehumidified
9-An Electrolux refrigerator is called:
(A) Single fluid absorption system
(B) Two fluid absorption system
(C) Three fluid absorption system
(D) Four fluid absorption system
10-Commonly used refrigerant in commercial ice plant is:
(A) Ammonia
(B) Freon-12
(C) Air
(D) CO2
11-Sling psychrometer is used to measure:
(A) only dry bulb temperature
(B) only wet bulb temperature
(C) dry and wet bulb temperature
(D) relative humidity
12-In refrigeration cycle, oil separator is fitted I between:
(A) Condenser and evaporator
(B) on the suction line
(C) compressor and condenser
(D) at the receiver outlet
13-The following is (are) the required characteristic(s) of refrigerant?
(A) high latent heat
(B) low boiling point
(C) high thermal conductivity
(D) all of the above
14-Accumulator is provided for
(A) storing of unvapourized liquid
(B) storing of liquid refrigerant
(C) exchange of heat
(D) condensing gas
15-HFC should not vent into atmosphere because:
(A) It is flammable in atmospheric temperature
(B) It has high global warming potential
(C) It is highly toxic
(D) It is very costly gas
16-Dehydrator is installed in
(A) liquid line
(B) discharge line
(C) suction line
(D) charging line
17-The difference between DBT and WBT is called:
(A) wet bulb difference
(B) dew point depression
(C) effective temperature
(D) adiabatic saturation temperature
18-Chemical name of Freon-22 is:
(A) Dichloro difluoro methane
(B) Monochloro difluoro methane
(C) Trichloro monofluoro methane
(D) Dicholoro monofluoro methane
19-Crisper temperature of refrigerator is equal to:
(A) 0°C
(B) 8°C
(C) -5°C
(D) None of the above
20-The oil used with R134a refrigerant is:
(A) Mineral oil
(B) Capilla D
(C) Polyol ester oil
(D) Lubricating oil
21-Which of the following refrigerant has the highest boiling point?
(A) Carbon di-oxide
(B) Ammonia
(C) Sulphur di-oxide
(D) Freon-12
22-Sum of atmospheric and gauge pressure is called
(A) Total pressure
(B) Absolute pressure
(C) Normal pressure
(D) Natural pressure
23-The effectiveness of the cooling tower is dependent on:
(A) Dry bulb temperature of the air
(B) Direction of the flow of air
(C) Wet bulb temperature of the air
(D) None of the above
ANSWERS:
1-(C), 2-(B), 3-(A), 4-(D), 5-(A), 6-(D), 7-(D), 8-(C), 9-(C), 10-(A), 11-(D), 12-(C), 13-(D), 14-(A), 15-(B), 16-(A), 17-(A), 18-(B), 19-(B), 20-(C), 21-(C), 22-(B), 23-(C)