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)