Question 1
Question
“Surging” would be best described as which of the following?
Answer
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A reversal of flow within the compressor
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A sudden increase in air temperature
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A sudden decrease in air temperature
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A malfunction caused by the micro- processing unit
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None of the above
Question 2
Question
Which of the following methods are used to control the load for rotary compressors?
Question 3
Question
Different methods used to control the load for a compressor include which of the following?
Question 4
Question
The free air capacities of axial flow compressors range form___m3 to___m3/min ?
Answer
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1.5- 200
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2.7-1500
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2.8- 3700
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1.9- 8000
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None of the above
Question 5
Question
What is the main advantage of an axial flow compressor?
Answer
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Low maintenance
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Higher efficiency
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Trouble free service
-
All of the above
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None of the above
Question 6
Question
Which of the following are advantages of the centrifugal compressor?
Question 7
Question
In a centrifugal compressor, energy is transferred from the impeller to the gas in the from of which of the following?
Answer
-
Velocity
-
Pressure
-
Velocity and pressure
-
All of the above
-
None of the above
Question 8
Question
In a rotary type screw compressor, the spiral valve is used to do which of the following?
Answer
-
Prevent dust and dirt from entering the compressor
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Regulate the amount of air to the compressor
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Open and close bypass ports in the stator
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All of the above
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None of the above
Question 9
Question
Which of the following devices removes any entrained moisture from the air leaving the compressor?
Answer
-
Fluid cooler
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Air after cooler
-
After filter
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Moisture separator
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None of the above
Question 10
Question
What is the main difference between the rotary compressor and the reciprocating compressor?
Question 11
Question
The most common designs of a rotary compressor are which of the following?
Sliding vane
Rotary lobe
Rotary screw
Sliding lobe
Rotary vane
Answer
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Sliding Vane, Rotary Lobe, Rotary vane
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Sliding Vane, Rotary Lobe, Rotary Screw
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Sliding Vane, Sliding Lobe, Rotary vane
Question 12
Question
External lubrication involves the lubrication of all moving parts external to the cylinder or casing, such as?
Piston
Crosshead
Crankshaft bearings
Connecting rod bearings
All of the above
Answer
-
Crosshead, crankshaft bearings, connecting rod bearings
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crankshaft bearings, crosshead, piston
Question 13
Question
Lubricating oil is necessary in a compressor to serve which of the following purposes?
Answer
-
Reduce friction
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Remove the heat produced by friction
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Coat the surfaces and reduce corrosion
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Provide a seal around the rings, vanes, and valves
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All of the above
Question 14
Question
If the cylinder of a reciprocating compressor is of oil free operation, the piston rings will be made of which of the following?
Answer
-
Stainless steel
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Cast iron
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Aluminum
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Teflon or carbon
-
All of the above
Question 15
Question
In a reciprocating compressor, air cooling has which of the following advantages over water cooling?
Answer
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Simple construction
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Less piping hazards
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No freezing
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All of the above
-
None of the above
Question 16
Question
In the _______________ compressor one of the cylinders acts as a cushion, while the other acts to compress the air?
Answer
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Tandem
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Free piston
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Single stage
-
Double stage
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None of the above
Question 17
Question
Reciprocating compressors may be divided into which of the following?
Answer
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Single stage
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Two stage
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Single acting
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Double acting
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Tandem
-
Free piston
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All of the above
Question 18
Question
Which of the following statements is true?
Answer
-
Compression ratio is the ratio of discharge gauge pressure to the intake absolute pressure
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A high compression ratio in a single cylinder results in a high volumetric efficiency and a high discharge temperature
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Intercoolers are used to cool the discharged air before it is delivered to it’s point of use or the receiver
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All of the above
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None of the above x
Question 19
Question
Intercoolers serve as a means to do which of the following?
Answer
-
Cool down the temperature of the air
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Remove any entrained moisture in the air
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Decrease the power required to compress the air in the following stage
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All of the above
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None of the above