Top 250+ Solved Refrigeration and Air conditioning MCQ Questions Answer
Q. The moisture in a refrigeration system is removed by
a. Driers
b. Dehumidifiers
c. Evaporators
d. Coolers
e. None of the above
Q. When ammonia is used as a refrigerant in vapour compression cycle, the mass circulated per ton of refrigerating effect will be nearly
a. 0.2 kg
b. 1 kg
c. 1.2 kg
d. 0.5 kg
e. 1.8 kg
Q. Which type of compressor is commonly used in room air-conditioner
a. Reciprocating
b. Rotory
c. Screw
d. Centrifugal
e. None of the above
Q. If the condensation temperature of a refrigerant is 25?C which type of condenser cannot be used?
a. Air cooled condenser
b. Water cooled condenser
c. Brine circulation condenser
d. Ice cooled condenser
e. Any of the above
Q. During air conditioning whenever two or more streams of moist air are mixed they follow
a. Isothermal process
b. Polytropic process
c. Constant pressure process
d. Polytropic process
e. Adiabatic process
Q. Air for air conditioning of aircraft cabin is obtained by
a. Compressing ambient air
b. Turbine exhaust
c. Bleeding from air compressor
d. Dehumidifying cabin air
e. Recycling cabin air
Q. Which of the following connections is usually not provided in a hermetically sealed type compressors?
a. Refrigerant inlet
b. Refrigerant outlet
c. Refrigerant charging connection
d. Lubricating oil charging connection
e. There is no connection provided
Q. In ammonia vapour compression system the temperature rise between the condenser outlet and the expansion valve should be
a. As high as possible to improve the performance
b. As high as possible to reduce motor power inputs
c. As little as possible for better performance
d. Anything as it has no bearing on the performance of system
e. None of the above
Q. "The difference between the length of a certain brass rod and that of a steel rod is clamped to be constant at all temperatures". The above statement
a. can never be true
b. can be valid only for temperatures below 0?C
c. can be true provided their lengths are directly proportional to the linear coefficients of the material of the rod
d. can be true provided their lengths are directly proportional to the linear coefficients of the material of the rod
e. None of the above
Q. PVC tubes are used for condenser and evaporator when the refrigerant is
a. Freon 12
b. Freon 22
c. Ammonia
d. Sulphur dioxide
e. None of the above
Q. Which reciprocating compressor is usually used in domestic refrigerators?
a. Open type
b. Semi-sealed type
c. Hermetically sealed type
d. Any of the above
e. None of the above
Q. A Carnot refrigerator extracts 100 kcal of heat per minute from a cold room which is maintained at - 15?C and it is discharged to atmosphere 30C?. The horse power required to run the unit would be
a. More than 6
b. 2 to 5
c. 5 to 6
d. 1.5 to 2
e. 1
Q. If space occupied by the refrigerating plant and cost is the major consideration, which of the following refrigerant will be preferred?
a. Carbondioxide
b. Sulphur dioxide
c. Mehtyl chloride
d. Ammonia
e. Any of the above
Q. When ammonia is the refrigerant, which of the following will be be the material for pipe through which refrigerant flows?
a. Cast steel or wrought iron
b. Copper
c. PVC
d. Brass
e. Aluminium