250+ TOP MCQs on Classification of Refrigerants and Answers

Refrigeration Multiple Choice Questions on “Classification of Refrigerants”.

1. Which of the following is not the type of refrigerant?
a) Organic refrigerants
b) Inorganic refrigerants
c) Azeotrope refrigerants
d) Halo-helium refrigerants
Answer: d
Clarification: Primary refrigerants are classified as Organic, i.e., Halo-Carbon refrigerants, Inorganic refrigerants, Azeotrope refrigerants, and Hydro-carbon refrigerants. Primary refrigerants are the one which takes a direct part in the refrigeration system.

2. When refrigerants take a direct part in the refrigeration system, then these types of refrigerants are called?
a) Primary
b) Secondary
c) Tertiary
d) Mixed
Answer: a
Clarification: Primary refrigerants are the one which takes a direct part in the refrigeration system. By absorbing the latent heat of vaporization effective refrigeration in produced.

3. The refrigerants which are first cooled by _________ refrigerants and then used for cooling purposes are known as ___________ refrigerants.
a) secondary, primary
b) primary, secondary
c) tertiary, primary
d) secondary, tertiary
Answer: b
Explanation Primary refrigerants are the one which takes a direct part in the refrigeration system. By absorbing the latent heat of vaporization effective refrigeration in produced. Whereas, refrigerants used for cooling purpose but firstly cooled by primary refrigerants are secondary refrigerants.

4. What is the number of halo-carbon compound refrigerants present as per ASHRAE?
a) 40
b) 41
c) 42
d) 43
Answer: c
Clarification: As per ASHRAE, i.e., American Society of Heating, Refrigeration and Air-conditioning Engineers, 42 Halo-carbon compounds are identified, but only a few are commonly used.

5. What does azeotrope mean?
a) Type of molecule
b) Type of bond
c) Stable mixture
d) Unstable mixture
Answer: c
Clarification: Azeotrope means a stable mixture of refrigerants; whose phases retain identical compositions over a large range of temperatures.

6. Which one of the following inorganic refrigerants is often used?
a) NH₃
b) CO₂
c) H₂O
d) SO₂
Answer: a
Clarification: Ammonia, i.e., NH₃, is widely used for the refrigeration system. Though it possesses high toxicity due to desirable properties to achieve maximum refrigeration effect is present, it is used frequently.

7. What is the refrigerant number of water?
a) R – 717
b) R – 744
c) R – 118
d) R – 100
Answer: c
Clarification: Water is having refrigerant number as R-118. Whereas, R-717, 744, 100 corresponds to Ammonia, Carbon dioxide, and ethyl chloride.

8. What is the number of halo-carbon compound refrigerants commonly used as per ASHRAE?
a) 42
b) 14
c) 41
d) 15
Answer: b
Clarification: As per ASHRAE, i.e., American Society of Heating, Refrigeration, and Air-conditioning Engineers, 42 Halo-carbon compounds are identified, but only a few are commonly used. The number of commonly used refrigerants is 14. Ex. R-11, 12, 13, 14, 21, 22, 30, 40, 100, 113, 114, 115, 123, 124, 134a, 152a.

9. Which of the following refrigerants are in the Freon group?
a) Organic refrigerants
b) Inorganic refrigerants
c) Azeotrope refrigerants
d) Hydrocarbon refrigerants
Answer: a
Clarification: Freon group is in the Organic or halo-carbon type of refrigerants. Halo-carbon compounds are produced and developed by freon family of refrigerants. Freon is the trademark of E.I. Du Pont de Nemours and Co., America.

10. Hydro-carbon refrigerants are commonly used nowadays.
a) True
b) False
Answer: b
Clarification: Hydro-carbons possess desired properties for refrigeration, but due to high flammability and explosive nature, hydrocarbons are replaced by another less explosive type of refrigerant.

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