Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: Whoever owns/uses a refrigeration or air conditioning system covered by this code

  • must notify the Department of Public Safety prior to starting the system
  • shall be licensed by the Commonwealth of Massachusetts according to CMR 522
  • shall make application for inspections to the Chief of Inspectors
  • None of the above

2: Brazed joints melt at temperatures above

  • 1,000F
  • 500F
  • 1,200F
  • 800F

3: 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

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

4: Which refrigerant is lighter than air?

  • R-717
  • R-11
  • R-123
  • R-134a

5: A premise or that portion of a premise where people transact business, receive personal service, or purchase foods, other goods is considered a

  • public assembly occupancy.
  • mercantile occupancy
  • business occupancy
  • commercial occupancy

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

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

7: copper and its alloys shall not be used in contact with _____ except as a component of bronze alloys for bearing or other non-refrigerant containing uses.

  • Lithium bromide
  • ammonia
  • HCFC-123
  • CFC-11

8: A restaurant is classified as a

  • commercial occupancy
  • mixed occupancy
  • large mercantile occupancy
  • public assembly occupancy

9: A secondary coolant is defined as

  • any refrigerant direcly in contact with the cooling space for process cooling
  • a low temperature refrigerant used for cascading systems
  • any liquid used for the transmission of heat without a change of state in A/C refrigeration systems having flash point above 150F
  • a combination of interconnected parts from a closed circuit in where fluid is circulated for the purpose of cooling for a refrigeration system.

10: Before you change the type of refrigerant in a refrigeration system, what three things must be done?

  • Nothing must be done
  • Place sign, check for leaks, and insulate suction line
  • Make sure its compatible, notify owner, and notify AHJ.
  • you can never change refrigerants

11: The actual expansion curve of compressor follows most nearly which one of the following

  • Isothermal
  • Pressure-Temperature
  • Volume
  • Adiabatic

12: The measurement of heat in a particular substance is

  • sensible heat
  • enthalpy
  • latent heat
  • specific heat

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

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

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

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

15: A total of all group A-2,B-2, A-3, and B-3 refrigerants shall not exceed ____ lb in the occupied areas and machinery rooms of institutional occupancies.

  • 50
  • 550
  • 350
  • 100

16: Refrigerants shall be classified by

  • toxicity and flammability
  • color codes
  • maximum permissible quantities of each group
  • requirements for commercial, industrial, and residential occupancies

17: Heat cannot of itself, pass from a

  • cold to a warmer body
  • warm to a colder body
  • state of hot energy to a state of cold energy
  • None of the above

18: The two basic types of evaporators are

  • flooded and direct expansion
  • prime surface and finned
  • direct expansion and plate
  • finned and plate

19: The rupture disc on a low-pressure chiller typically releases pressure at

  • 0 psig
  • 5 psig
  • 15 psig
  • 10 psig

20: In a motor, an internal overload might open if

  • there's an excess current draw through the motor
  • there was a high pressure refrigerant was used for a low pressure system.
  • there's an open start winding
  • there's a direct short

21: Name an HCFC refrigerant(s):

  • R-22
  • R-123
  • R-11
  • both a & b

22: It shall be the duty of the person in charge of the premises on which a refrigeration system containing more than ___ lbs of refrigerant is installed to provide a schematic drawing or panel giving directions for the operation of the system.

  • 75
  • 50
  • 55
  • 15

23: If your suction line is warmer than the room temperature, this may indicate

  • an over charge
  • plugged air filter
  • below normal superheat
  • a low charge

24: The high side float assembly meters refrigerant into the evaporator through the

  • lower chamber of the low side
  • upper chamber of the high side
  • lower chamber of the high side
  • upper chamber of the low side

25: Sublimation occurs when

  • gas is formed directly from a solid
  • ice melts and turns to water
  • gas is formed from a liquid
  • liquid is formed from a gas