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REFRIGERANTS MULTIPLE CHOICE QUESTIONS (MCQ) WITH ANSWERS

 

REFRIGERANTS MULTIPLE

CHOICE QUESTIONS (MCQ)

WITH ANSWERS

Refrigerant in a refrigeration system

is like blood circulation in the human

body. It causes cooling by latent heat

of vaporization. Refrigerant should be

non-corrosive, non decomposable,

non-toxic and inert to the materials of

construction. In the event of leakage, it

must not chemically react with food stuff

as in a refrigerator. It must be cheap and

available in abundance. Air is primary

refrigerant in air craft refrigeration, It is

a  secondary refrigerant in a fridge. It is

tertiary refrigerant in a central air

conditioning system.

Leakage

The refrigeration system should be leak

proof. Leakage in a system is known by

soap solution/halide torch/electronic

detector. Before refilling of refrigerant into

a system it must be ensured for leak proof

by vacuum and pressure testing. Leakage

of Freon’s add to global warming and

ozone depletion. Water, air, ammonia,

carbon dioxide do not add to global

warming and ozone depletion.

Fig. Halide Torch

Fig. Numbering of Organic Refrigerants

Fig. Types of Refrigerants

Q1. Refrigerant used should be such that its normal boiling point is

(a) > the temperature required
(b) < the temperature required
(c) = the temperature required
(d) None
(Ans: b)

Q2. Pressure of refrigerant in the evaporator should be

(a) = the atmospheric pressure
(b) < the atmospheric pressure
(c) > the atmospheric pressure
(d) None

ANS: (c)

Q3. Latent heat is highest for

(a) Refrigerant – 22
(b) Ammonia
(c) Water
(d) None
(Ans: c)

Q4. Specific heat at constant pressure is highest

(a) Refrigerant – 22
(b) Ammonia
(c) Water
(d) None
(Ans: c)

Q5. Specific heats at constant pressure and at constant volume are equal for

(a) Vapor Refrigerant – 22
(b) Vapor Ammonia
(c) Water vapors
(d) None
(Ans: d)

Q6. Cp of air is

(a) > Cv of air
(b) = Cv of air
(c) < Cv of air
(d) None
(Ans: c)

Q7. Primary refrigerant is one which is sensibly

(a) Heated in the evaporator
(b) Cooled in the evaporator
(c) Both (a) & (b)
(d) None
(Ans: d)

Q8. Cooling of the secondary refrigerant is by

(a)  Water
(b)  Air
(c)  Primary refrigerant
(d) None
(Ans: c)
Q9. Which acts as a primary, secondary & a tertiary refrigerant? 

 (a) Water
(b) Ammonia
(c) Freon-22
(d) None
(Ans: d)

Q10. Which acts as a primary, secondary & a tertiary refrigerant?

(a) Water
(b) Air
(c) Freon- 22
(d) None
(Ans: b)

Q11. Which is the primary refrigerant in central air conditioning plant?

(a) Air
(b) Water
(c) Freon-22
(d) None
(Ans: c)

Q12. Which is the secondary refrigerant in central air conditioning plant?

(a) Air
(b) Water
(c) Freon-22
(d) None
(Ans: b)

Q13. Which is the tertiary refrigerant in central air conditioning plant?

(a) Air
(b) Water
(c) Freon-22
(d) None
(Ans: a)

Q14. Which is the secondary refrigerant in an ice plant?

(a) Air
(b) Water
(c) Freon-22
(d) None
(Ans: d)

Q15. Which is the secondary refrigerant in an ice plant?

(a) Mercury
(b) Brine solution
(c) Freon-22
(d) None
(Ans: b)

Q16. Which is the secondary refrigerant in an window air conditioner?

(a) Water
(b) Brine solution
(c) Air
(d) None
(Ans: c)

Q17. Which is the most desirable property of a refrigerant?

(a) It should be toxic.
(b) It should be non-corrosive.
(c) It has least enthalpy of vaporization
(d) None

ANS: (b)

Q18.  The refrigerant widely used for cooling of food stuff?

(a) Ammonia

(b) Sulphur dioxide

(c) Ethyl chloride

(d) None

ANS: (d)

Q19. Refrigerants having maximum ozone depletion potential are

  1. Ammonia, Air

  2. R-11 and R-22

  3. R-11 & R-12

  4. None

ANS: ©

Q20. Refrigerants having maximum Global warming potential are

  1. Ammonia, Air

  2. R-11 and R-22

  3. Water and Sulphur dioxide

  4. None

ANS: (d)

Q21. Montreal protocol on refrigerants deals with

  1. Ozone depletion potential

  2. Global warming potential

  3. Both (a) and (b)

  4. None

ANS: (a)

Q22. Montreal protocol on refrigerants deals with phase out of

  1.  Ammonia

  2.  Propane

  3.  Halogenated hydrocarbons

  4. None

ANS: (c)

Q23. Kyoto protocol on climate change deals with

  1. Phase out of halogenated hydrocarbons

  2. Limit and reduce Green House Gases emissions from all sources

  3. Control of ozone depletion

  4. None

ANS: (b)

q24. The Kigali Amendment deals with phase out of

  1.  Hydrocarbons by cutting their production and consumption

  2.  HFC by cutting their production and consumption

  3.  Ammonia and Sulphur dioxide by cutting their production and consumption

  4. None

ANS: (b)

Q25. Montreal protocol happened in

  1. 1987

  2. 1989

  3. 1991

  4. None

ANS: (a)

Q26. Kyoto agreement took place in

  1. 1991

  2. 1997

  3. 2001

  4. None

ANS: (b)

Q27. The Kigali agreement took place in

  1. 2012

  2. 2014

  3. 2016

  4. None

ANS: (c)

Q28. Which type of leakage of refrigerant is more harmful?

  1. Inward leakage

  2. Outward leakage

  3. Both (a) & (b)

  4. None

ANS: (a)

Q29. Leaked refrigerant should not have a chemical reaction with the

  1. Materials of construction

  2. Stored food stuff

  3. Both (a) & (b)

  4. None

ANS: (c)

Q30. Vacuum testing of a refrigeration system regarding leakage, fill the system with

  1. Nitrogen

  2. Hydrogen

  3. Air

  4. None

ANS: (d)

Q31. Universal method of refrigerant leak detection is

(a) Halide leak detector
(b) Electronic leak detector
(c) Soap solution method
(d) None

(Ans: c)

Q32. Which method of refrigerant leak detection is valid for Ammonia?

(a) Halide leak detector
(b) Electronic leak detector
(c) Soap solution method
(d) None
(Ans: c)

Q33. Which condition must be satisfied before filling refrigerant into a refrigeration unit

(a) Water proof
(b) Air proof
(c) Leak Proof
(d) None

(Ans: c)

Q34. Which test must be conducted before filling refrigerant into the refrigeration unit?

(a) Air Test
(b) Pressure Test
(c) Water Test
(d) Refrigerant test

(Ans: b)

Q35. Which test must be conducted before filling refrigerant into the refrigeration unit
(a) Air Test
(b) Water Test
(c) Vacuum Test
(d) Refrigerant test

(Ans: c)

Q36. For how much time, for detecting outward leakage, pressure be stored in the system

(a) 12 hours

(b) 6 hours

(c) 18 hours

(d) None

(Ans: d)

Q37. For how much time, for detecting outward leakage point, pressure be stored in the system

(a) 36 hours

(b) 24 hours

(c) 18 hours

(d) None

(Ans: b)

Q38. For how much time, for detecting inward leakage point, vacuum be stored in the system

(a) 12 hours

(b) 6 hours

(c) 18 hours

(d) None

(Ans: d)

Q39. For how much time, for detecting inward leakage point, pressure be stored in the system

(a) 36 hours

(b) 24hours

(c) 18 hours

(d) None

(Ans: b)

Q40. Halide torch is used to detect the leakage of

(a)R-22, R-134a and R-22

(b) R-717, R-718 and R-729

(c) Carbon dioxide

(d) None

(Ans: a)

Q41. In the event of leakage, which refrigerant is most dangerous?

(a) Sulphur Dioxide

(b) Ammonia

(c) Carbon dioxide

(None

(Ans: a)

Q42. Which refrigerant is the most costly?

(a) Ammonia

(b) Freon

(c) Carbon dioxide

(d) None

(Ans: b)

Q43. Highest working pressures are found in case of

(a) Ammonia

(b) Freon

(c) Carbon dioxide

(d) None

(Ans: c)

Q44. Which refrigerant add to global warming?

(a)Ammonia

(b) Air

(c) Water

(d) None

ANS: (d)

Q45. Which refrigerant add to global warming?

(a) Ammonia

(b) Carbon dioxide

(c) Freon-134

(d) None

ANS: (c)

Q46. Which refrigerant create ozone depletion?

(a) Water

(b) Air

(c) Ammonia

(d) None

ANS: (d)

Q47. Which refrigerant create ozone depletion?

(a) Air

(b) carbon dioxide

(c) Freon-22

(d) None

ANS: (c)

 

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