The wet bulb depression indicates _________ humidity of the air.
Absolute
Relative
Specific
None of these
Correct Answer :
B. Relative
Related Questions
The condition of refrigerant as it leaves the compressor in a vapour compression system is
Saturated liquid
Wet vapour
Dry saturated vapour
Superheated vapour
The refrigerant widely used in domestic refrigerators is
Ammonia
Carbon dioxide
Sulphur dioxide
R-12
An infinite parallel planes with emissivities e₁ and e₂, the interchange factor for radiation from surface 1 to surface 2 is given by
(e₁ + e₂)/ e₁ + e₂ - e₁e₂
1/e₁ + 1/e₂
e₁ + e₂
e₁e₂
In a vapour compression cycle, the refrigerant immediately after expansion valve is
Liquid
Sub-cooled liquid
Saturated liquid
Wet vapour
Air refrigeration cycle is used in
Commercial refrigerators
Domestic refrigerators
Air-conditioning
Gas liquefaction
A Bell Coleman refrigerator working on dense air system as compared to open air system, for the same range of temperature, results in ________ power per tonne of refrigeration.
Same
Lower
Higher
None of these
The wet bulb temperature during sensible heating of air
Remains constant
Increases
Decreases
None of these
Dry bulb temperature is the temperature of air recorded by a thermometer, when
It is not affected by the moisture present in the air
Its bulb is surrounded by a wet cloth exposed to the air
The moisture present in it begins to condense
None of the above
Which of the following cycles uses air as the refrigerant?
Ericson
Stirling
Carnot
Bell Coleman
The wet bulb temperature at 100% relative humidity is ________ dew point temperature.
Same as
Lower than
Higher than
None of these
The refrigerant used in small tonnage commercial machines (hermetically sealed units) is
Ammonia
Carbon dioxide
Sulphur dioxide
R-12
For obtaining high COP, the pressure range of compressor should be
High
Low
Optimum
Any value
During heating and dehumidification process, dry bulb temperature
Remains constant
Increases
Decreases
None of these
Choose the correct statement
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
The emissivity of a polished silver body is __________ as compared to black body.
Same
Low
Very low
High
The Freon group of refrigerants are
Halocarbon refrigerants
Zoetrope refrigerants
Inorganic refrigerants
Hydrocarbon refrigerants
The vapour pressure of refrigerant should be
Lower than atmospheric pressure
Higher than atmospheric pressure
Equal to atmospheric pressure
Could be anything
In which of the following refrigeration system, waste heat can be effectively used?
Vapour compression cycle
Vapour absorption cycle
Air refrigeration cycle
None of these
Critical pressure of a liquid is the pressure
Above which liquid will remain liquid
Above which liquid becomes gas
Above which liquid becomes vapour
Above which liquid becomes solid
For unsaturated air, the dew point temperature is __________ wet bulb temperature.
Equal to
Less than
More than
None of these
In chemical dehumidification process,
Dew point temperature decreases
Wet bulb temperature decreases
Dry bulb temperature increases
All of these
In a vapour compression system, the condition of refrigerant before passing through the condenser is
Saturated liquid
Wet vapour
Dry saturated vapour
Superheated vapour
Rick up the incorrect statement
Lithium bromide used in vapour absorption cycle is non volatile
Lithium bromide plant can't operate below 0°C
A separator is used in lithium bromide plant to remove the unwanted water vapour by condensing
Concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator
The value of C.O.P in vapour compression cycle is usually
Always less than unity
Always more than unity
Equal to unity
Any one of the above
The material of pipe lines for a system using Freon as a refrigerant should be
Brass
Copper
Steel
Aluminium
Air refrigeration operates on
Carnot cycle
Reversed Carnot cycle
Rankines cycle
Brayton cycle
In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to
Collect liquid refrigerant and prevent it from going to compressor
Detect liquid in vapour
Superheat the vapour
Collect vapours
One tonne of refrigeration (1TR) means that the heat removing capacity is
21 kJ/min
210 kJ/min
420 kJ/min
620 kJ/min
The dry bulb temperature during sensible heating of air
Remains constant
Increases
Decreases
None of these
One ton refrigeration corresponds to
50 kcal/ min
50 kcal/ hr
80 kcal/ min
80 kcal/ hr