Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: Foaming of oil in a compressor is most likely to occur

  • when there is insufficient air across the condenser(i.e., dirty coil)
  • when the evaporator temperatures are below 32F
  • at start-up
  • when ambient temperature are low

2: What happens to copper joints when overheated?

  • nothing
  • joint becomes oxidized and ditorted
  • copper becomes harder
  • none of the above

3: The most common type of motor starter is

  • part winding starter
  • delts-wye starter
  • duel-winding starter
  • across the line starter

4: The main purpose of a refrigerant detector in a machinery room is to

  • inform there is a refrigerant leak int he system
  • detect toxins in the air caused by a refrigerant leak
  • to set off an alarm when there is refrigerant present inside the room
  • all of the above

5: Sensible heat is the heat added to a substance to

  • cause evaporation
  • raise its temperature
  • freeze it
  • change its state

6: When energized, a normally open relay will be

  • closed
  • open
  • depends on the type and class of the relay
  • noisy

7: R-12. R-22, and R-40 are considered Group I refrigerants.

  • True
  • False

8: What is the typical air conditioning operating pressures for R-22?

  • 60 psi suction 210 psi discharge
  • 25 psi suction 125 psi discharge
  • 105 psi suction 340 psi discharge
  • None of the above

9: Heat that changes the physical state of a substance without effecting a change in its temperature is known as

  • latent heat
  • lost heat
  • specific heat
  • sensible heat

10: Joints in piping for refrigeration containing parts must withstand temperatures of ___?

  • 1000F
  • 800F
  • 600F
  • 700F

11: A motor starter is a device that includes an overload and a _______?

  • contactor
  • 2-pole contacts
  • duel-coil
  • all of the above

12: On a large centrifugal system, what meters the flow to the evaporator?

  • Cap tube.
  • Low side float
  • TXV
  • High side float

13: 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

14: Atmospheric pressure is equal to

  • 29.92" Hg
  • 14.7 psia
  • 14.7 psig
  • both a & b

15: A machine room with a refrigerant system using ammonia shall

  • be provided with a continuously operated ventilation system
  • be considered a non-hazardous location in accordance with National Electrical code
  • have no flame producing apparatus permanently installed and operated
  • All of the above

16: How many volts would you read on a 480V system phase to phase?

  • 480
  • 0
  • 1/3 the voltage
  • 277

17: If two 500 ohm resistors are connected in series, the resistance will be

  • 1000 ohms
  • 200 ohms
  • 20 ohms
  • 500 ohms

18: 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

19: Refrigerant restricted in 2004 but used for transition for decades:

  • R-22
  • R-123
  • R-11
  • R-134A

20: What chemical in the refrigerant set off the leak detection alarm?

  • Fluorine
  • Chlorine
  • Both A and B
  • none of the above

21: When releasing a hydrogenated hydrocarbon refrigerant to the atmosphere, ample ventilation must be provided and

  • explosion precautions must be taken
  • gas masks must be worn
  • no flames shall be permitted
  • the owner shall be informed

22: A pressure relief should be located at least _______ from windows and doors.

  • 30'
  • 20'
  • 25'
  • 15'

23: An azeotropic refrigerant is

  • a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
  • a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
  • a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
  • none of the above

24: Where is an EPR valve located on a multi-evaporator system?

  • Suction line of the coolest evaporator
  • Suction line at the compressor
  • Suction line of the warmest evaporator
  • Suction line prior to the accumulator of the lowest temperature system

25: Relief valves are rated in

  • gallons of water per hour
  • pounds of air per hour
  • pounds of air per minute
  • gallons of water per minute