Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: Refrigerant restricted in 2004 but used for transition for decades:
R-11
R-134A
R-22
R-123
2: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
pick up voltage
boost voltage
lift voltage
run voltage
3: Pairs of mating stop valves that allow sections of a system to be joined before opening these valves or separated after closing them are
gate or globe valves
ball valves
companion or block valves
king valves
4: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
77F
58F
70F
32F
5: Machinery rooms shall be vented to _____________ and utilizing mechanical ventilation.
the mechanical room housing the refrigeration system
Machinery rooms need not be vented
the return air ducted system
the outdoors
6: What device should be used on low-temperature freezers?
high capacity TXV
oil separator
discharge muffler
hot-gas by-pass
7: If the compression ratio on a centrifugal compressor rises too high, the compressor will stop pumping and make a loud sound commonly referred to as a
purge
surge
merge
splurge
8: Group A1 refrigerants over ____ pounds in a system must discharge to the atmosphere
6.6
110
1,000
330
9: What instrument is used to measure very high resistance?
voltmeter
meg ohmmeter
ammeter
tape measure
10: A R-22 system running with a condensing temperature of 110F and a 40F evaporator temperature will read pressures of ____ on the high side and ____ on the low side.
350 psig, 120 psig
257 psig, 77 psig
455 psig, 185 psig
226 psig, 68 psig
11: A run capacitor is wired in series with the _____ windings.
start capacitor
start
common
run
12: Laten heat is associated with a change in state of a refrigerant but not temperature
True
False
13: Halogenated refrigerants cannot be used with what material?
Copper
Magnesium alloy
Aluminum
Stainless steel
14: Pressure vessel having an inside diameter exceeding 6” with an internal pressure greater than 15psig shall be marked directly on or on the nameplate the letters _______________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
“UM” and “UV”
“UL”
“UV”
“U” or “UM”
15: A hotel is considered a _______ occupancy.
commercial
mercantile
residential
institutional
16: Adjusting the spring pressure on a TXV
changes subcooling
changes superheat
adjusts the bulb charge
makes no difference
17: How many opening forces operate a thermostatic expansion valve?
2
4
1
3
18: Pressure vessels with an internal volume of 10 cubic feet or more
shall use fusible plugs
shall use pressure relief devices or fusible plugs
shall use pressure relief devices
shall use rupture discs or duel pressure relief valves
19: Sensible heat is the heat added to a substance to
raise its temperature
change its state
cause evaporation
freeze it
20: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.
there is no Group B1 refrigerants
the same
lower
higher
21: What measures gas pressure?
Barometer
Hydrometer
Hygrometer
Manometer
22: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
50
18
33
22
23: Dual-pressure relief devices should be installed on
vessels of 3 cubic feet or more
vessels of 10 cubic feet or less
vessels of 3 cubic feet or less
vessels of 10 cubic feet or more
24: A restaurant is classified as a
commercial occupancy
mixed occupancy
public assembly occupancy
large mercantile occupancy
25: Which of the following is not an air velocity meter?