Is less than 1
Is more than 1
Is equal to 1
Depends upon the make
B. Is more than 1
Same as
Lower than
Higher than
None of these
Equal to
Less than
Greater than
None of these
Water and hydrogen
Ammonia and hydrogen
Ammonia, water and hydrogen
None of these
Wet bulb temperature
Relative humidity
Dry bulb temperature
Specific humidity
[T₁ (T₂ - T₃)] / [T₃ (T₁ - T₂)]
[T₃ (T₁ - T₂)]/ [T₁ (T₂ - T₃)]
[T₁ (T₁ - T₂)] / [T₃ (T₂ - T₃)]
[T₃ (T₂ - T₃)] / [T₁ (T₁ - T₂)]
Low weight per tonne of refrigeration
High heat transfer rate
Low temperature at high altitudes
Higher coefficient of performance
Increase
Decrease
May increase or decrease depending on the type of refrigerant used
Remain unaffected
-20.5°C
-50°C
-63.3°C
-78.3°C
A refrigerant should have low latent heat
If operating temperature of system is low, then refrigerant with low boiling point should be used
Pre-cooling and sub-cooling bf refrigerant are same
Superheat and sensible heat of a refrigerant are same
Domestic refrigerators
Water coolers
Room air conditioners
All of these
Cooled and humidified
Cooled and dehumidified
Heated and humidified
Heated and dehumidified
Ensures the evaporator completely filled with refrigerant of the load
Is suitable only for constant load systems
Maintains different temperatures in evaporator in proportion to load
None of the above
Cost is too high
Capacity control is not possible
It is made of copper
Required pressure drop cannot be achieved
Positive
Negative
Zero
None of these
Humidification
Dehumidification
Heating and humidification
Cooling and dehumidification
Higher in winter than in summer
Lower in winter than in summer
Same in winter and summer
Not dependent on season
It is toxic to mucous membranes.
It requires large displacement per TR compared to fluoro carbons.
It reacts with copper and its alloys.
All of these
Compressor
Condenser
Expansion valve
Evaporator
The mass of water vapour present in 1 m³ of dry air
The mass of water vapour present in 1 kg of dry air
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.
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
Circulating more quantity of cooling water through the condenser
Using water colder than the main circulating water
Employing a heat exchanger
Any one of the above
Copper
Aluminium
Steel
Brass
Lithium bromide is used as a refrigerant and water as an absorbent
Water is used as a refrigerant and lithium bromide as an absorbent
Ammonia is used as a refrigerant and lithium bromide as an absorbent
None of the above
Water
Ammonia
Freon
Aqua-ammonia
It permits higher speeds to be used
It permits complete evaporation in the evaporator
It results in high volumetric and mechanical efficiency
All of the above
Condenser
Evaporator
Absorber
None of these
Non-toxic
Non-flammable
Non-explosive
High boiling point
Dew point temperature of air
Wet bulb temperature of air
Dry bulb temperature of air
Ambient air temperature
Remains constant
Increases
Decreases
None of these
Compression
Direct
Indirect
Absorption
The performance of the vapour compression refrigerator varies considerably with both vaporising and condensing temperatures.
In vapour compression cycle, the useful part of the heat transfer is at the condenser.
In ammonia-hydrogen (Electrolux) refrigerator, no compressor, pump or fan is required.
The effect of under-cooling the liquid refrigerant is to decrease the coefficient of performance.