Freon group of refrigerants are
Inflammable
Toxic
Non-inflammable and toxic
Nontoxic and non-inflammable
Correct Answer :
D. Nontoxic and non-inflammable
Related Questions
Bell Coleman cycle is a
Reversed Carnot cycle
Reversed Otto cycle
Reversed Joule cycle
Reversed Rankine cycle
Which of the following statement is correct?
The constant enthalpy lines are also constant wet bulb temperature lines.
The wet bulb and dry bulb temperature are equal at saturation condition.
The wet bulb temperature is a measure of enthalpy of moist air.
All of the above
The evaporator changes the low pressure liquid refrigerant from the expansion valve into
High pressure liquid refrigerant
Low pressure liquid and vapour refrigerant
Low pressure vapour refrigerant
None of these
A standard ice point temperature corresponds to the temperature of
Water at 0°C
Ice at 4°C
Solid and dry ice
Mixture of ice and water under equilibrium conditions
Mass flow ratio of NH₃ in comparison to Freon12 for same refrigeration load and same temperature limits is of the order of
1 : 1
1 : 9
9 : 1
1 : 3
Critical temperature is the temperature above which
A gas will never liquefy
A gas will immediately liquefy
Water will evaporate
Water will never evaporate
In vapour compression refrigeration system, refrigerant occurs as liquid between
Condenser and expansion valve
Compressor and evaporator
Expansion valve and evaporator
Compressor and condenser
Vapour compression refrigeration is somewhat like
Carnot cycle
Rankines cycle
Reversed Carnot cycle
None of the above
The bank of tubes at the back of domestic refrigerator is
Condenser tubes
Evaporator tubes
Refrigerant cooling tubes
Capillary tubes
The material of pipe lines for a system using Freon as a refrigerant should be
Brass
Copper
Steel
Aluminium
The lowest thermal diffusivity is of
Iron
Lead
Aluminium
Rubber
Which of the following refrigerant has the highest freezing point.
Ammonia
Carbon dioxide
Sulphur dioxide
R-12
The leakage in a refrigeration system using ammonia is detected by
Halide torch
Sulphur sticks
Soap and water
All of these
The coefficient of performance of Electrolux refrigerator is the ratio of
Heat supplied by the gas burner to the heat absorbed by the evaporator
Heat absorbed by the evaporator to the heat supplied by the gas burner
Heat supplied by the gas burner minus the heat absorbed by the evaporator to the heat supplied by the gas burner
Heat absorbed by the evaporator minus the heat supplied by the gas burner to the heat absorbed by the evaporator
Refrigeration in aeroplanes usually employs the following refrigerant
CO2
Freon-11
Freon-22
Air
The reciprocating refrigerant compressors are very suitable for
Small displacements and low condensing pressures
Large displacements and high condensing pressures
Small displacements and high condensing pressures
Large displacements and low condensing pressures
In vapour compression cycle using NH₃ as refrigerant, initial charge is filled at
Suction of compressor
Delivery of compressor
High pressure side close to receiver
Low pressure side near receiver
In a vapour compression refrigeration system, a throttle valve is used in place of an expander because
It considerably reduces mass of the system
It improves the C.O.P., as the condenser is small
The positive work in isentropic expansion of liquid is very small
It leads to significant cost reduction
Aqua ammonia is used as refrigerant in the following type of refrigeration system
Compression
Direct
Indirect
Absorption
In a vapour compression system, the condition of refrigerant before entering the expansion or throttle valve is
High pressure saturated liquid
Wet vapour
Very wet vapour
Dry vapour
Which of the following is not a desirable property of a refrigerant?
High risibility with oil
Low boiling point
Good electrical conductor
Large latent heat
Which of the following refrigerant has the lowest freezing point?
R-11
R-12
R-22
Ammonia
The optimum effective temperature for human comfort is
Higher in winter than in summer
Lower in winter than in summer
Same in winter and summer
Not dependent on season
A refrigeration cycle operates between condenser temperature of + 27°C and evaporator temperature of -23°C. The Carnot coefficient of performance of cycle will be
0.2
1.2
5
6
During sensible cooling of air ________ decreases.
Wet bulb temperature
Relative humidity
Dry bulb temperature
Specific humidity
A pressure gauge on the discharge side of a refrigerant compressor reads too high. The reasons will be
Lack of cooling water
Water temperature being high
Dirty condenser surface
All of these
During a refrigeration cycle, heat is rejected by the refrigerant in a
Compressor
Condenser
Evaporator
Expansion valve
Which of the following refrigerant is highly toxic and flammable?
Ammonia
Carbon dioxide
Sulphur dioxide
R-12
During dehumidification process, __________ remains constant.
Wet bulb temperature
Relative humidity
Dry bulb temperature
Specific humidity
Highest pressure encountered in a refrigeration system should be
Critical pressure of refrigerant
Much below critical pressure
Much above critical pressure
Near critical pressure