260 Important Refrigeration And Air Conditioning MCQ Question and Answer | PDF Free Download
1.If a gas is to be liquefied, its temperature must be
- AIncreased to a value above its critical temperature
- BReduced to a value below its critical temperature
- CEqual to critical temperature
- DNone of the above
2.The relative coefficient of performance is equal to
- A(Theoretical C.O.P.)/ (Actual C.O.P.)
- B(Actual C.O.P.) /(Theoretical C.O.P.)
- C(Actual C.O.P.) × (Theoretical C.O.P.)
- DNone of these
3.The C.O.P. of a refrigerator working on a reversed Carnot cycle is (where T₁ = Lowest absolute temperature, and T₂ = Highest absolute temperature)
- AT₁ / (T₂ - T₁)
- B(T₂ - T₁)/T₁
- C(T₁ - T₂)/T₁
- DT₂/ (T₂ - T₁)
4.The wet bulb temperature during sensible heating of air
- ARemains constant
- BIncreases
- CDecreases
- DNone of these
5.The vapour pressure of refrigerant should be
- ALower than atmospheric pressure
- BHigher than atmospheric pressure
- CEqual to atmospheric pressure
- DCould be anything
6.The material of pipe lines for a system using Freon as a refrigerant should be
- ABrass
- BCopper
- CSteel
- DSteel
7.The ratio of heat extracted in the refrigerator to the work-done on the refrigerant is called
- ACoefficient of performance of refrigeration
- BCoefficient of performance of heat pump
- CRelative coefficient of performance
- DRefrigerating efficiency
8.The specific humidity during humidification process
- ARemains constant
- BIncreases
- CDecreases
- DNone of these
9.The specific humidity during dehumidification process
- ARemains constant
- BIncreases
- CDecreases
- DNone of these
10.The capillary tube is not used in large capacity refrigeration systems because
- ACost is too high
- BCapacity control is not possible
- CIt is made of copper
- DRequired pressure drop cannot be achieved
11.Highest temperature encountered in refrigeration cycle should be
- ANear critical temperature of refrigerant
- BAbove critical temperature
- CAt critical Temperature
- DMuch below critical temperature
12.The higher temperature in vapour compression cycle occurs at
- AReceiver
- BExpansion valve
- CEvaporator
- DCompressor discharge
13.The leaks in a refrigeration system using Freon are detected by
- AHalide torch which on detection produces greenish flame lighting
- BSulphur sticks which on detection gives white smoke
- CUsing reagents
- DSmelling
14.The condensing pressure due to the presence of non-condensable gases, as compared to that actually required for condensing temperatures without non-condensable gases
- AWill be higher
- BWill be lower
- CWill remain unaffected
- DMay be higher or lower depending upon the nature of non-condensable gases
15.In order to collect liquid refrigerant and to prevent it from going to a ________, a device known as accumulator is used at the suction of compressor.
- ACompressor
- BCondenser
- CExpansion valve
- DEvaporator
16.The leakage in a refrigeration system using Freon is detected by
- AHalide torch
- BSulphur sticks
- CSoap and water
- DAll of these
17.Ammonia absorption refrigeration cycle requires
- AVery little work input
- BMaximum work input
- CNearly same work input as for vapour compression cycle
- DZero work input
18.One ton refrigeration corresponds to
- A50 kcal/ min
- B50 kcal/ hr
- C80 kcal/ min
- D80 kcal/ hr
19.A mixture of dry air and water vapour, when the air has diffused the maximum amount of water vapour into it, is called
- ADry air
- BMoist air
- CSaturated air
- DSpecific humidity
20.The superheated vapour region, in a pressure enthalpy chart, is represented by the space
- ATo the left of saturated liquid line
- BTo the right of saturated liquid line
- CBetween the saturated liquid line and saturated vapour line
- DNone of the above