Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: A solder joint melts at temperatures of

  • less than 400F
  • 1,200F to 1,500F
  • 400F to 800F
  • 600F to 900F

2: Absolute pressure is

  • Gauge Pressure
  • Atmospheric Pressure
  • Gauge + Atmospheric Pressure + Pi
  • none of the above

3: Which of the following types of oils are hygroscopic?

  • polyolester (POE)
  • polyalkylene glycol (PAG)
  • naphthene mineral
  • both a and b

4: How much refrigerant can be stored in a mechanical room outside of the system?

  • 330
  • 100
  • 150
  • 200

5: When energized, a normally open relay will be

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

6: A hissing noise at the expansion valve is a good indication that

  • liquid is passing thru it
  • expansion valve is oversized
  • gas is passing thru it
  • nothing is passing thru

7: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?

  • duel-voltage switch
  • centrifugal switch
  • printed circuit board (PCB)
  • motor starter

8: On a TXV, the purpose of an external equalizer is to?

  • Increase the pressure on the top of the power head diaphragm
  • compensate for a pressure drop across the evaporator coil
  • allow a greater adjustment spam
  • balance the evaporator load

9: An air conditioning system rated for 36,000 BTU's is equivalent to

  • three tons of cooling
  • two tons of cooling
  • 12,000 tons of cooling
  • one ton of cooling

10: Increasing superheat will do what to your frost line?

  • Increasae
  • Nothing
  • Decrease
  • Could either increase or decrease depending on the load conditions

11: Pipe identification labels are required when the system contains more than

  • 110 lbs
  • 55 lbs
  • 120 lbs
  • 65 lbs

12: When an A/C system is excessively low on refrigerant

  • it can become contaminated with water
  • there can be nuisance trip outs
  • the suction line may be too hot to touch
  • All of the above

13: What type of relief valve is used on low pressure centrifugal compressor systems?

  • Spring-loaded relief valve
  • Rupture disc
  • Purge relief
  • None of the above

14: High side floats are used on centrifugal chiller systems are are considered critically charged systems.

  • are obsolete.
  • False
  • True
  • depends on the type of refrigerant being used

15: A VRF system is a direct system

  • true
  • false

16: What device should be used on low-temperature freezers?

  • hot-gas by-pass
  • high capacity TXV
  • oil separator
  • discharge muffler

17: 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

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

  • 90%
  • 75%
  • 99%
  • 80%

19: one BTU equals

  • 31.4 hp
  • 12,000 hp
  • 3.41 hp
  • Pi

20: A thermometer inside a duct measures ____ heat.

  • specific
  • sensible
  • hidden
  • latent

21: Calculate the voltage in a series circuit when the total amperage is 10 amps and the resistors have values of: R1=12 ohms, R2=8 ohms, R3=4 ohms

  • 2,400 volts
  • 2.40 volts
  • 24.0 volts
  • 240 volts

22: Can you use Ammonia in industrial applications?

  • Yes, Under certain condidtions
  • When mixed with R-718
  • Yes, always
  • No, never

23: The density of a gas refers to

  • pounds per cubic foot
  • pounds per square foot
  • pounds per absolute pressure
  • cubic feet per pound

24: Give an example of a secondary coolant?

  • R-12
  • R-410A
  • R-717
  • R-718

25: A 24 volt transformer with a 240 volt primary can handle how many amps?

  • 10 amps
  • There isn't enough information to answer.
  • 20 amps
  • 24 amps