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
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