Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: System design pressures must take into consideration, not only, pressures found during normal operation but also what?
When it's cold out
When there is a malfunction on the high side
When its warm out
All of the above
2: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
2.5 times the design pressure
the aggregate of the high side and low side
the high side
the low side
3: Capacity control on a centrifugal compressor is accomplished by the
check valves
pre-rotational guide vanes
post-rotational guide vanes
slide vanes
4: A solder joint melts at temperatures of
1,200F to 1,500F
400F to 800F
less than 400F
600F to 900F
5: What is not a requirement of a class T machine room?
automatic ventilation
tight fitting doors
fire hose connection to the building fire protection system
self-closing doors
6: Which refrigerant is lighter than air?
R-11
R-134a
R-123
R-717
7: How are a compressor and condenser fan wired?
series-parallel
series
parallel-series
parallel
8: What effect does the temperature of air have on humidity?
warmer air holds more moisture then cooler air
cooler air holds more moisture then warmer air
air has no effect of humidity
none of the above
9: When can 50/50 solder be used?
in the low side
in the high side
liquid and suction lines
none of the above.
10: When releasing a hydrogenated hydrocarbon refrigerant to the atmosphere, ample ventilation must be provided and
the owner shall be informed
explosion precautions must be taken
gas masks must be worn
no flames shall be permitted
11: What instrument is used to measure very high resistance?
ammeter
meg ohmmeter
tape measure
voltmeter
12: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
500 lbs
330 lbs
660 lbs
55 lbs
13: What type of pressure relief device is used on a CO2 system?
Glove valve
Fusible plug
Gate valve
Rupture disk
14: The start winding has _____ turns than the run winding.
more
less
the same
none of the above
15: Halogenated refrigerants cannot be used with what material?
Aluminum
Magnesium alloy
Stainless steel
Copper
16: The density of a gas refers to
pounds per cubic foot
cubic feet per pound
pounds per square foot
pounds per absolute pressure
17: Class 3 refrigerants are
non-flammable
highly flammable
toxic
non-toxic
18: At higher altitudes, the boiling point of refrigerant is
the same
higher
equal to the coefficient of water at 32F
lower
19: If your suction line is warmer than the room temperature, this may indicate
below normal superheat
plugged air filter
an over charge
a low charge
20: The first step in mechanical refrigeration is
evaporation
compression
expansion
condensation
21: A motor starter is a device that includes an overload and a _______?
contactor
2-pole contacts
duel-coil
all of the above
22: Joints in refrigeration piping must be _____ before being covered?
Insulated
Pressurized
Inspected
Leak tested
23: Which of the following most closely represents the concentration of Li-Br in a absorption system?
50% Li-Br, 50% tap water
40% Li-Br, 60% distilled water
40% Li-Br, 60% tap water
60% Li-Br, 40% distilled water
24: One atmosphere equals
0 psia
14.7
29.4
0 psig
25: A total of all group A-2,B-2, A-3, and B-3 refrigerants shall not exceed ____ lb in the occupied areas and machinery rooms of institutional occupancies.