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?

• Hydrometer
• Velometer
• Anemotherm
• Anemometer