The critical pressure is the pressure_____
Above which explosion of liquid occurs
Above which a liquid will remain a liquid
Above which a liquid turns into a vapour
Below which a liquid remains only in the liquid state
Which of the following pair of refrigerants is both non-toxic and non-inflammable?
NH3 and SO2
CO2 and SO2
CO2 and F12
F12 and NH3
Which of the following refrigerants has the minimum freezing point?
Ammonia
Carbon dioxide
Freon-12
Freon-22
The refrigerant commonly used for commercial ice plants is
Freon-12
NH3
CO2
Air
The Freon group of refrigerant are
Inorganic refrigerants
Hydrocarbon refrigerants
Halo-carbon refrigerants
Azeotraope refrogerants
The chemical formula of Freon-12 is
CCI F2
CCI2 F3
CCI2 F2
CCIF
The refrigerant Freon-12 is a compound consisting of
Corbon, hydrogen and fluorine
Carbon, hydrogen and chlorine
Carbon, chlorine and fluorine
Carbon, hydrogen, chlorine and fluorine
Which of the following pair of refrigerants is both colourless and odourless?
Carbon dioxide and Freon-12
Sulphur dioxide and carbon dioxide
Freon-12 and ammonia
Carbon dioxide and ammonia
Which of the following refrigerants has the lowest specific volume?
Carbon dioxide
Ammonia
Freon-12
Freon-22
Identify the refrigerant with highest toxicity
Freon-12
Ammonia
Sulphur dioxide
Carbon dioxide
Ammonia is preferred as a refrigerant in large commercial installations because
It is non-toxic
It has low latent heat
It has low working pressure
It is relatively cheap
R-12 is generally preferred over R-22 in deep freezers since
It has low operating pressures
It gives high coefficient of performance
It is miscible with oil over large range of temperatures
It is non-toxic and non-inflammable
Suggest the material to be used for the pipes and pipe fittings in an ammonia refrigerantion plant
Aluminium
Brass
Copper
Cast steel or wrought iron
Identify the refrigerant used for refrigeration purposes in passenger aircraft
Freon-12
Carbon dioxide
Air
Sodium chloride
The wet bulb depression is zero when relative humidity equals
Zero
0.5
0.75
1.0
Which of the following parameters remains constant during adiabatic saturation process on unsaturated air?
Dry bulb temperature
Wet bulb temperature
Dew point temperature
Relative humidity