Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

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

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

2: "E" represents _____ in the Watt's law formula.

  • voltage
  • watts
  • reactance
  • amperage

3: Ammonia (NH3) is a group III refrigerant

  • True
  • False

4: A EPR valve is installed on what type of evaporators?

  • low-temperature evaporators
  • shell and tube evaporators
  • high-temperature evaporators
  • plate evaporators

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

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

6: What is the refrigerant dichlorodifluoromethane?

  • R-22
  • R-134A
  • R-123
  • R-12

7: A capacitor in series with the start windings will do what?

  • Increase starting torque
  • Nothing
  • Decrease the RLA to within 10% of its rating
  • Increase run efficiency by 10% of its rating

8: The amount of heat required to raise the temperature of 1 lb of water 1F is?

  • The rate of conduction
  • 1 Kelvin
  • 1 Therm
  • 1 BTU

9: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed

  • 330 lbs.
  • 660 lbs
  • 550 lbs
  • 55 lbs

10: What must be done to refrigerant pipes before being buried?

  • Encased
  • Coated
  • Leaked checked
  • Certified

11: The freezing point of water at sea level is?

  • 32C
  • 32F
  • 0F
  • -10C

12: Ammonia systems use ____ pressure to adjust oil pressure

  • liquid
  • discharge
  • stream
  • air

13: What effect does the temperature of air have on humidity?

  • warmer air holds more moisture then cooler air
  • cooler air holds more moisture then warmer air
  • air has no effect of humidity
  • none of the above

14: A compressor in which the increase in vapor pressure is attained without changing the internal volume of the compression chamber is called

  • negative displacement compressor
  • non-volumetric displacement compressor
  • neutral chamber-type compressor
  • non-positive displacement compressor

15: R-22 falls under which safety classification?

  • A-2
  • B-2
  • A-1
  • B-1

16: Capacity control on a centrifugal compressor is accomplished by the

  • slide vanes
  • post-rotational guide vanes
  • check valves
  • pre-rotational guide vanes

17: Which refrigerant was still able to be vented to the atmosphere after July 1, 1992?

  • R-22
  • R-113
  • R-12
  • R-11

18: A high side float is a

  • float type switch that stops the compressor when the pressure on the high side becomes too high
  • float type valve that controls the amount of refrigerant stored in the receiver
  • float type valve that controls the crankcase oil level
  • metering device used on critically charged systems that controls the level of the liquid refrigerant in the high pressure side of the system.

19: Class 3 refrigerants are

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

20: 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

21: Laten heat is associated with a change in state of a refrigerant but not temperature

  • True
  • False

22: How are refrigerant blends classified?

  • Based on the oil used
  • Based on worst case fractionation
  • Blends don't have to be classified
  • Based on best case Fractionation

23: Defined process piping by code CMR (528)

  • Any piping that conveys a solid, liquid or gas that is not part of the plumbing or fire protection system
  • Any piping in an industrial space
  • Any piping in an industrial or commercial space
  • All of the above

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

  • 99%
  • 80%
  • 75%
  • 90%

25: Where would the EPR valve be located on a multiple evaporator system?

  • outlet of high temperature evaporator
  • inlet of the low temperature evaporator.
  • outlet of low temperature evaporator
  • outlet of the liquid line