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WorksheetsRAC Basic refrigeration & refrigerants QUIZ
Total questions: 27
Worksheet time: 26mins
A reversible Carnot cycle used for refrigeration
comprises
Two isentropic and two adiabatic processes
Two isentropic and two constant volume processes
Two isentropic and two constant pressure process
Two isentropic and two isothermal processes
The heat removing capacity of one tone of refrigeration is equal to?
210 Watt
210 kJ/hour
3.5 kJ/hour
3.5 kW
The COP of a refrigerator is 4. What will be the COP of a heat pump if it is working between same source and sink temperature ?
2
3
4
5
One tonne of refrigeration is equal to
21 KJ/min
210 KJ/min
420 KJ/min
620 KJ/min
One tonne of refrigerating machine means that,
One tonne is the total mass of the machine
One tonne of refrigerant is used
One tonne of water can be converted into ice.
One tonne of ice when melts from and at 0oC in 24 hours, the refrigerating effect produced is equivalent to 210 KJ/min
In a refrigerating machine, heat rejected is ............ heat absorbed.
Equal to
Less than
Greater than
partially less than
The C.O.P. of a heat pump working on a reversed Carnot cycle is ( T₂- high temperature, T₁ - Low Temperature)
(A) T₁/(T₂ - T₁)
(B) (T₂ - T₁)/T₁
(C) (T₁ - T₂)/T₁
(D) T₂/(T₂ - T₁)
If a heat pump cycle operates between the condenser temperature of +27°C and evaporator temperature of -23°C, then the Carnot COP will be
(A) 0.2
(B) 1.2
(C) 5
(D) 6
A reversible engine has ideal thermal efficiency of 30%. When it is used as a refrigerating machine with all other conditions unchanged, the coefficient of performance will be
(A) 1.33
(B) 2.33
(C) 3.33
(D) 4.33
ODP stands for
Outdoor Dangerous Pollution
Over Demanding Protocol
Ozone Depletion Protocol
Ozone Depletion Potential
Which of the following refrigerants are phased-out due to Montreal protocol on ozone layer depletion-
R11
R21
R12
R32
TEWI stands for
Total Energy Work Interaction
Total Equivalent Warming Index
Total Equivalent Work Index
Transfer of Energy With Intensity
A refrigerant should have
High ODP
High GWP
Low ODP
Low GWP
The chemical formula of refrigerant R11 is:
CCl3F
CClF3
CClHF
CHF
The chemical formula of R141 is:
C2H3ClF3
C2H2Cl3F
C2H3Cl2F
C2H2ClF3
Secondary refrigerants are also called as
Coolers
Brines
Wines
Synthetic Solutions
Azeotropic mixtures are
100 series
500 series
400 series
1000 series
Inorganic compounds are
500 series
200 series
700 series
1000 series
The reference gas used in calculation of ODP is:
CO2
CFC
NO2
Hydrocarbons
The reference gas used in calculation of GWP is:
CFC
Bromine
CO2
NH3
R717 is refrigerant name for
Water
Carbon dioxide
Ammonia
Air
For the refrigernat R134a, 'a' stands for:
isomers
Epimers
isotopes
Derivation
Which of the following refrigerants are suggested as replacements for R22 in large air conditioning and cold storage systems?
R134a
R21
R410A
R407C
Which of the following statements is TRUE?
Evaporation process is non-isothermal for zeotropic mixtures
Evaporation process is non-isothermal for azeotropic mixtures
Composition of azeotropic mixture changes in the event of a leak
Composition of zeotropic mixture changes in the event of a leak
Which of the following statements are TRUE?
The suction pressure of a refrigerant should be as high as possible
The suction pressure of a refrigerant should be as low as possible
The discharge pressure of a refrigerant should be as high as possible
The discharge pressure of a refrigerant should be as low as possible
Which of the following statements are TRUE?
A primary refrigerant does not undergo phase change in a refrigeration cycle
A secondary refrigerant does not undergo phase change in a refrigeration cycle
The freezing point of a brine is generally lower than the freezing point of its constituents
The freezing point of a brine is generally higher than the freezing point of its constituents
According to ASHRAE, Refrigerants belonging to Group A1 are__________ , while refrigerants belonging to Group B3 are ___________
most hazardous, least hazardous
least hazardous, most hazardous
