Heat Transfer, Refrigeration and Air Conditioning

41. The sensible heat gain is due to the __________ difference between the fresh air and the air in space.

A. temperature
B. humidity


Correct Answer: A. temperature

42. During cooling and dehumidification, dry bulb temperature

A. remains constant
B. increases
C. decreases


Correct Answer: C. decreases

43. The coefficient of performance of Electrolux refrigerator is the ratio of

A. heat supplied by the gas burner to the heat absorbed by the evaporator
B. heat absorbed by the evaporator to the heat supplied by the gas burner
C. heat supplied by the gas burner minus the heat absorbed by the evaporator to the heat supplied by the gas burner
D. heat absorbed by the evaporator minus the heat supplied by the gas burner to the heat absorbed by the evaporator


Correct Answer: B. heat absorbed by the evaporator to the heat supplied by the gas burner

44. The sulfur sticks, in case of leakage of ammonia refrigerant, gives white smoke.

A. True
B. False


Correct Answer: A. True

45. During gas charging in an ammonia vapor compression system, the connection is made at the compressor outlet.

A. Agree
B. Disagree


Correct Answer: A. Agree

46. The conditioned air supplied to the room must have the capacity to take up

A. room sensible heat load only
B. room latent heat load only
C. both room sensible heat and latent heat loads
D. none of the above


Correct Answer: C. both room sensible heat and latent heat loads

47. The process of removing moisture from the air, without change in its dry bulb temperature, is called dehumidification.

A. Correct
B. Incorrect


Correct Answer: A. Correct

48. The specific humidity during dehumidification process

A. remains constant
B. increases
C. decreases


Correct Answer: C. decreases

49. Which of the following refrigerant has the lowest freezing point?

A. R-11
B. R-12
C. R-22
D. Ammonia


Correct Answer: C. R-22

50. For a white body, absorptivity (α ) = 0, reflectivity (ρ) = 1 and transmittivity (τ) = 0.

A. Correct
B. Incorrect


Correct Answer: A. Correct

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