mcq: Refrigerants

mcq: Refrigerants 

 

 

Refrigerant in a refrigeration system is lie 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. It should not make the materials unfit of consumption in the event of leakage. it must be cheap with avail plant.ability in abundance. Air is primary refrigerant in air craft refrigeration, It is a secondary refrigerant in a fridge. It is tertiary in a central air conditioning

Refrigerant used should be such that its normal boiling point is
(a) Greater than the temperature required
(b) Less than the temperature required
(c) Equal to the temperature required
(d) None
(Ans:b)

Pressure of refrigerant in the evaporator should be
(a) Equal to the atmospheric pressure
(b) Less than the atmospheric pressure
(c) Greater than the atmospheric pressure
(d) None
(Ans:c)

Latent heat is highest for
(a) Refrigerant – 22
(b) Ammonia
(c) Water
(d) None
(Ans:c)

Specific heat at constant pressure is highest
(a) Refrigerant – 22
(b) Ammonia
(c) Water
(d) None
(Ans:c)

Specific heats at constant pressure and at constant volume are equal
(a) Vapor Refrigerant – 22
(b) Vapor Ammonia
(c) Water vapors
(d) None
(Ans:d)

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

Primary refrigerant is one which is sensibly
(a) Heated in the evaporator
(b) Cooled in the evaporator
(c) Neither heated in evaporator nor cooled in condenser
(d) None
(Ans:d)

Secondary refrigerant is one which is
(a) Cooled by the water
(b) Cooled by the air
(c) Cooled by the primary refrigerant
(d) None
(Ans:c)
Which one acts as a primary, secondary as well as a tertiary refrigerant  
(a) Water
(b) Ammonia
(c) Freon-22
(d) None
(Ans:d)

Which one acts as a primary, secondary as well as a tertiary refrigerant
(a) Water
(b) Air
(c) Freon- 22
(d) None
(Ans:b)

Which is the primary refrigerant in central air conditioning plant
(a) Air
(b) Water
(c) Freon-22
(d) None
(Ans:c)

Which is the secondary refrigerant in central air conditioning plant
(e) Air
(f) Water
(g) Freon-22
(h) None
(Ans:b)

Which is the tertiary refrigerant in central air conditioning plant
(i) Air
(j) Water
(k) Freon-22
(l) None
(Ans:a)

Which is the secondary refrigerant in an ice plant
(i) Air
(j) Water
(k) Freon-22
(l) None
(Ans:d)

Which is the secondary refrigerant in an ice plant
(i) Mercury
(j) Brine solution
(k) Freon-22
(l) None
(Ans:b)

Which is the secondary refrigerant in an window air conditioner
(i) Water
(j) Brine solution
(k) Air
(l) None
(Ans:c)