260 Important Refrigeration And Air Conditioning MCQ Question and Answer | PDF Free Download
1.Degree of saturation or percentage humidity is
- AThe mass of water vapour present in 1 m³ of dry air
- BThe mass of water vapour present in 1 kg of dry air
- CThe 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
- DThe 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
2.In larger industrial and commercial reciprocating compression systems, refrigerant widely used is
- AAmmonia
- BCarbon dioxide
- CSulphur dioxide
- DR-12
3.A heat pump working on a reversed Carnot cycle has a C.O.P. of 5. It works as a refrigerator taking 1 kW of work input. The refrigerating effect will be
- A1 kW
- B2 kW
- C3 kW
- D4 kW
4.The bypass factor for a cooling coil
- AIncreases with increase in velocity of air passing through it
- BDecreases with increase in velocity of air passing through it
- CRemains unchanged with increase in velocity of air passing through it
- DMay increase or decrease with increase in velocity of air passing through it depending upon the condition of air entering
5.A bootstrap air cooling system has
- AOne heat exchanger
- BTwo heat exchangers
- CThree heat exchangers
- DFour heat exchangers
6.The reduced ambient air cooling system has
- AOne cooling turbine and one heat exchanger
- BOne cooling turbine and two heat exchangers
- CTwo cooling turbines and one heat exchanger
- DTwo cooling turbines and two heat exchangers
7.In a psychrometric chart, specific humidity (moisture content) lines are
- AVertical and uniformly spaced
- BHorizontal and uniformly spaced
- CHorizontal and non-uniformly spaced
- DCurved lines
8.Bell Coleman cycle is a
- AReversed Carnot cycle
- BReversed Otto cycle
- CReversed Joule cycle
- DReversed Rankine cycle
9.The wet bulb temperature at 100% relative humidity is ________ dew point temperature.
- ASame as
- BLower than
- CHigher than
- DNone of these
10.The relative coefficient of performance is
- AActual COP/theoretical COP
- BTheoretical COP/actual COP
- CActual COP × theoretical COP
- DNone of these
11.Which of the following is not a desirable property of a refrigerant?
- AHigh risibility with oil
- BLow boiling point
- CGood electrical conductor
- DLarge latent heat
12.One ton of refrigeration is equal to the refrigeration effect corresponding to melting of 1000 kg of ice
- AIn 1 hour
- BIn 1 minute
- CIn 24 hours
- DIn 12 hours
13.Absorption system normally uses the following refrigerant
- AFreon-11
- BFreon-22
- CCO2
- DAmmonia
14.Refrigeration in aeroplanes usually employs the following refrigerant
- ACO2
- BFreon-11
- CFreon-22
- DAir
15.One tonne of refrigeration (1TR) means that the heat removing capacity is
- A21 kJ/min
- B210 kJ/min
- C420 kJ/min
- D620 kJ/min
16.For large tonnage (more than 200 TR) air-conditioning applications, the compressor recommended is
- AReciprocating
- BRotating
- CCentrifugal
- DScrew
17.Most thermostatic expansion valves are set for a superheat of
- A5°C
- B10°C
- C15°C
- D20°C
18.The refrigerant supplied to a compressor must be
- ASuperheated vapour refrigerant
- BDry saturated liquid refrigerant
- CA mixture of liquid and vapour refrigerant
- DNone of these
19.Where does the lowest temperature occur in a vapour compression cycle?
- ACondenser
- BEvaporator
- CCompressor
- DExpansion valve
20.The relative humidity lines on a psychrometric chart are
- AVertical and uniformly spaced
- BHorizontal and uniformly spaced
- CHorizontal and non-uniformly spaced
- DCurved lines