Engineering :: Refrigeration and Air conditioning
11.
In a mechanical refrigeration system the refrigerant occurs as liquid (or very wet vapour) between
A.
Compressor outlet and condenser
B.
Condenser and expansion valve
C.
Expansion valve or evaporator
D.
Evaporation valve and compressor
E.
Before and after compressor
Answer: Option B
Explanation:
12.
A device designed to remove moisture from a refrigerant is called
A.
Expansion valve
B.
Dehumidifier
C.
Drier
D.
Solenoid
E.
Humidstat
Answer: Option C
Explanation:
13.
A desicant is
A.
A solid substance capable of removing moisture from a gas, liquid or solid
B.
A substance which reduces the viscosity of liquids
C.
Heat given off by cargo
D.
A process of removing heat under controlled conditions
E.
Anammonia and a water solution
Answer: Option A
Explanation:
14.
Freon 12 is a compound consisting of stoms of
A.
Carbon, hydrogen and fluorine
B.
Carbon, hydrogen and oxygen
C.
Carbon, hydrogen, fluorine and chlorine
D.
Carbon, fluorine and chlorine
E.
Carbon and hydrogen
Answer: Option D
Explanation:
15.
The condition of refrigerant before and after the expansion or throttle valve in a vapour compression system is
A.
Wet vapour, very wet vapour
B.
Wet vapour, dry vapour
C.
High pressure saturated liquid, very wet vapour
D.
Very wet vapour, high pressure, saturated liquid
E.
None of the above
Answer: Option C
Explanation:
16.
In a vapour absorption refrigeration system the power is required for vapour compressor as compared to that in vapour compression cycle is
A.
More
B.
Less
C.
Half
D.
One forth
E.
There is no such relation
Answer: Option E
Explanation:
17.
In a ammonia vapour compression cycle during gas charging the connection is made
A.
Anywhere in the cycle
B.
At the compressor cycle
C.
At the compressor outlet
D.
On low pressure side near evaporat
E.
On high pressure side close to receiver
Answer: Option E
Explanation:
18.
In a newly charged ammonia compression system, the clicking sound in the expansion valve indicates
A.
High pressure after compression
B.
Excessive ammonia charged
C.
Lack of ammonia
D.
Evaporator coils chocked
E.
Leakage of ammonia
Answer: Option C
Explanation:
19.
Air and other non-condensable gases (foul gases) get into a refrigeration system through
A.
Decomposition of refrigerant in contact with impurities
B.
Breakdown of oil
C.
Under vacuum operation or during maintenance work
D.
Corrosion
E.
Any of the above
Answer: Option E
Explanation:
20.
A plant has one 300 ton and one 500 ton centrifugal unit. The total flow of brine is 6400 litres per minute. What should be the distribution of brine flow through each unit
A.
3200 litres each
B.
2400 litres through 300 ton plant and 4000 litres through 500 ton plant
C.
4000 litres through 300 ton plant and 2400 litres through 500 ton plant
D.
Same brine should flow through both
E.
None of the above
Answer: Option C
Explanation:
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