260 Important Refrigeration And Air Conditioning MCQ Question and Answer | PDF Free Download
1.Highest pressure encountered in a refrigeration system should be
- ACritical pressure of refrigerant
- BV
- CMuch above critical pressure
- DNear critical pressure
2.In a vapour compression system, the condition of refrigerant before passing through the condenser is
- ASaturated liquid
- BWet vapour
- CDry saturated vapour
- DSuperheated vapour
3.Which of the following cycles uses air as the refrigerant?
- AEricson
- BStirling
- CCarnot
- DBell Coleman
4.The heat rejection factor (HRF) is given by
- A1 + C.O.P
- B1 - C.O.P.
- C1 + (1/C.O.P)
- D1 - (1/C.O.P)
5.In a spray washing system, if the temperature of water is higher than the dry bulb temperature of entering air, then the air is
- AHeated and dehumidified
- BHeated and humidified
- CCooled and humidified
- DCooled and dehumidified
6.In vapour compression cycle using NH₃ as refrigerant, initial charge is filled at
- ASuction of compressor
- BDelivery of compressor
- CHigh pressure side close to receiver
- DLow pressure side near receiver
7.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
- A0.2
- B1.2
- C5
- D6
8.Vertical lines on pressure-enthalpy chart show constant
- APressure lines
- BTemperature lines
- CTotal heat lines
- DEntropy lines
9.A vapour absorption refrigerator uses _________ as a refrigerant.
- AWater
- BAmmonia
- CFreon
- DAqua-ammonia
10.Which of the following statement is correct for ammonia as a refrigerant?
- AIt is toxic to mucous membranes.
- BIt requires large displacement per TR compared to fluoro carbons.
- CIt reacts with copper and its alloys.
- DAll of these
11.In vapour compression refrigeration system, refrigerant occurs as liquid between
- ACondenser and expansion valve
- BCompressor and evaporator
- CExpansion valve and evaporator
- DCompressor and condenser
12.The total pressure exerted by the mixture of air and water vapour is equal to the sum of pressures which each constituent would exert, if it occupied the same space by itself. This statement is called
- AKinetic theory of gases
- BNewton's law of gases
- CDalton's law of partial pressures
- DAvogadro's hypothesis
13.In S.J. unit, one ton of refrigeration is equal to
- A210 kJ/ min
- B21 kJ/ min
- C420 kJ/ min
- D840 kJ/ min
14.The humidification process, on the psychrometric chart is shown by
- AHorizontal line
- BVertical line
- CInclined line
- DCurved line
15.On the pressure-enthalpy diagram, condensation and desuperheating is represented by a horizontal line because the process
- AInvolves no change in volume
- BTakes place at constant temperature
- CTakes place at constant entropy
- DTakes place at constant pressure
16.Carbon dioxide is
- AColourless
- BOdourless
- CNon-flammable
- DAll of these
17.The C.O.P. of a Carnot refrigerator in winter will be _________ as compared to C.O.P. in summer.
- ASame
- BLower
- CHigher
- DNone of these
18.The bank of tubes at the back of domestic refrigerator is
- ACondenser tubes
- BEvaporator tubes
- CRefrigerant cooling tubes
- DCapillary tubes
19.Critical temperature is the temperature above which
- AA gas will never liquefy
- BA gas will immediately liquefy
- CWater will evaporate
- DWater will never evaporate
20.The C.O.P. of an absorption type refrigerator is given by (where T₁ = Temperature at which the working substance receives heat, T₂ = Temperature of cooling water, and T₃ = Evaporator temperature)
- A[T₁ (T₂ - T₃)] / [T₃ (T₁ - T₂)]
- B[T₃ (T₁ - T₂)]/ [T₁ (T₂ - T₃)]
- C[T₁ (T₁ - T₂)] / [T₃ (T₂ - T₃)]
- Dv