Objective type questions on refrigeration and air conditioning - Set 14 - ObjectiveBooks

# Practice Test: Question Set - 14

1. The temperature of air recorded by a thermometer, when its bulb is surrounded by a wet cloth exposed to the air, is called
(A) Wet bulb temperature
(B) Dry bulb temperature
(C) Dew point temperature
(D) None of these

2. The C.O.P. of an absorption type refrigerator is given by (where T₁ = Temperature at which the working substance receives heat, T₂ = Temperature of cooling water, and T₃ = Evaporator temperature)
(A) [T₁ (T₂ - T₃)] / [T₃ (T₁ - T₂)]
(B) [T₃ (T₁ - T₂)]/ [T₁ (T₂ - T₃)]
(C) [T₁ (T₁ - T₂)] / [T₃ (T₂ - T₃)]
(D) [T₃ (T₂ - T₃)] / [T₁ (T₁ - T₂)]

3. The humidity ratio or specific humidity is the mass of water vapour present in
(A) 1 m3 of wet air
(B) 1 m3 of dry air
(C) 1 kg of wet air
(D) 1 kg of dry air

4. During adiabatic saturation process on unsaturated air __________ remains constant.
(A) Relative humidity
(B) Dew point temperature
(C) Dry bulb temperature
(D) Wet bulb temperature

5. Degree of saturation or percentage humidity is
(A) The mass of water vapour present in 1 m³ of dry air
(B) The mass of water vapour present in 1 kg of dry air
(C) The ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure
(D) The ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure

6. The reciprocating refrigerant compressors are very suitable for
(A) Small displacements and low condensing pressures
(B) Large displacements and high condensing pressures
(C) Small displacements and high condensing pressures
(D) Large displacements and low condensing pressures

7. The desirable property of a refrigerant is
(A) Low boiling point
(B) High critical temperature
(C) High latent heat of vaporisation
(D) All of these

8. The humidification process, on the psychrometric chart is shown by
(A) Horizontal line
(B) Vertical line
(C) Inclined line
(D) Curved line

9. The evaporator used in household refrigerators is
(A) Frosting evaporator
(B) Non-frosting evaporator
(C) Defrosting evaporator
(D) None of these

10. In case of sensible heating of air, the coil efficiency is given by (where B.P.F. = Bypass factor)
(A) B.P.F. - 1
(B) 1 - B. P.F.
(C) 1/ B.P.F.
(D) 1 + B.P.F.

11. In a refrigerating machine, heat rejected is _________ heat absorbed.
(A) Equal to
(B) Less than
(C) Greater than
(D) None of these

12. In aqua ammonia and Lithium bromide water absorption refrigeration systems, the refrigerants are respectively
(A) Water and water
(B) Water and lithium bromide
(C) Ammonia and lithium bromide
(D) Ammonia and water

13. In air-conditioning of aeroplanes, using air as a refrigerant, the cycle used is
(A) Reversed Carnot cycle
(B) Reversed Joule cycle
(C) Reversed Brayton cycle
(D) Reversed Otto cycle

14. The mass of water vapour present in __________ is called absolute humidity.
(A) 1 m3 of water
(B) 1 m3 of dry air
(C) 1 kg of wet air
(D) 1 kg of dry air

15. While designing the refrigeration system of an aircraft, the prime consideration is that the
(A) System has high C.O.P.
(B) Power per TR is low
(C) Mass of refrigerant circulated in the system is low
(D) Mass of the refrigeration equipment is low

Show and hide multiple DIV using JavaScript View All Answers

Blogger Comment