Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: When using nitrogen for brazing, the pressure should be:

  • 125 psig
  • 50-100 psig
  • Slightly below atmospheric
  • Very low

2: Pressure is equivalent of

  • Area X Force
  • Force
  • Force / Area
  • Force X Area

3: Large Mercantile occupancy is a premise or that portion of a premise where more than ____ persons congregate on levels above or below the street level to purchase personal merchandise.

  • 100
  • 250
  • 350
  • 400

4: According to ASHRAE Standard-15 9.8 Positive Displacement Compressor Protection, the pressure-relief device discharge into

  • the low-pressure side of the system
  • the high side of the system
  • the liquid receiver
  • both a and c are correct

5: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?

  • 15 amps
  • 10 amps
  • 20 amps
  • 5 amps

6: If the spring is adjusted to increase the superheat, this new setting will

  • have no effect on the frost line
  • lengthen the frost line
  • shorten the frost line
  • allow more liquid into the evaporator

7: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.

  • 75%
  • 99%
  • 90%
  • 80%

8: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.

  • 24
  • 15
  • 18
  • 10

9: Which is the lowest vacuum?

  • 5" hg
  • 5 psig
  • 1,000 Microns
  • 10 psia

10: How is bring measured?

  • anemometer
  • hydrometer
  • hygrometer
  • manometer

11: The 522 CMR 9.00 has adopted for reference ASHRAE ____

  • 25
  • III
  • 15
  • 10

12: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is

  • Latent heat
  • Specific heat
  • Enthalpy
  • Sensible heat

13: A room having machinery but no flame producing apparatus permanently installed and operated is considered a

  • Class A machinery room
  • Class M machinery room
  • Class B machinery room
  • Class T machinery room

14: Class A refrigerants are considered

  • non-flammable
  • toxic
  • non-toxic
  • flammable

15: What type of fuses must be used on a HVAC system?

  • TR Type, Duel Element, Time Delay
  • Fast blow
  • 10% lower than RLA
  • none of the above

16: 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

17: After setting up a forward curved fan for the desired conditions, something happened to lower the total static pressure the fan had to operate against. Which would occur?

  • RPM and CFM increase
  • CFM and HP decrease
  • CFM and RPM decrease
  • CFM and HP increase

18: A self contained system

  • is any system or part of a system used to increase evaporation by expansion or vaporization
  • is a unit system Group I refrigerants only
  • is a complete factory made and tested system
  • is a unit system Group II refrigerants only

19: If air is present in an absorption chilled water appliance, which of the following will most likely occur?

  • System operating pressure will drop
  • The Li-Br solution will become more diluted
  • The Li-Br solution will become more concentrated
  • Rust can form

20: On a single phase motor, when does the start winding cut out?

  • 100% of its RLA speed
  • 25% of its RLA speed
  • 75% of its RLA speed
  • 50% of its RLA speed

21: Horizontal piping should be run level.

  • False
  • Yes, if the condenser is located above the evaporator
  • True
  • No, unless the supervisor on the job says so.

22: In an A/C unit, dirty filters will cause

  • high discharge pressure
  • low oil pressure
  • low suction pressure
  • high suction pressur

23: A Lithium-bromide system is an absorption system that

  • uses ammonia as a refrigerant and lithium bromide as an absorbent
  • uses water as a refrigerant and lithium bromide as an absorbent
  • uses water as a absorbent and lithium bromide as a refrigerant
  • uses salts as an absorbent and lithium bromide as a refrigerant

24: R-717 is

  • ammonia
  • trichloromethane
  • water
  • carbon dioxide

25: A R-410A system running with a condensing temperature of 110F and 50F evaporator temperature will read pressures of ___ on the high side and ___ on the low side

  • 365 psig, 120 psig
  • 455 psig, 185 psig.
  • 226 psig, 68 psig
  • 257 psig, 77 psig