Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: On a centrifugal compressor, stationary diffuser vanes are needed to

  • prevent high pressure on the packing
  • convert velocity energy to pressure
  • stop gas flow
  • increase the clearance space

2: The Board of Boilers adopts by reference

  • Montreal Protocol Safety Code
  • the 1997 ANSI/ASHRAE Safety Code
  • MSCA Code
  • the MACS Pressure Vessel Code of Massachusetts

3: R-718 is rated unlimited for refrigeration quantity contained in a system. Why?

  • Because it's water
  • Because it's a non-flammable refrigerant
  • Because it's cheap
  • R-718 is not rated unlimited because it's a dangerous refrigerant

4: Which is considered the more efficient condenser?

  • fan cooled
  • air cooled
  • spray cooled
  • water cooled

5: The gauge thickness required on a CO2 tank construction is

  • 1/16"
  • 1/8"
  • 3/32"
  • 5/16"

6: When systems are protected by a high pressure relief device, the compressor's pressure limiting device shall be set at or below ____ % of the operating pressure of the high side relief device.

  • 90
  • 100
  • 110
  • 80

7: The actual expansion curve of compression follows most nearly which one of the following curves?

  • Volume Temperature
  • Pressure Temperature
  • Adiabatic
  • Isothermal

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

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

9: A split-phase motor has a ______ winding and a ____ winding

  • duel-run, duel-start
  • start, common
  • run, start
  • run, common

10: Ammonia shall be discharged into ____________ or a tank containing one gallon of water for every pound of ammonia.

  • the atmosphere
  • a de-pressurized recovery tank with a silver top and yellow bottom
  • a tank containing two pounds of a water/lithium bromide mix for every pound of ammonia
  • All of the above

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

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

12: What happens to copper joints when overheated?

  • nothing
  • joint becomes oxidized and ditorted
  • copper becomes harder
  • none 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: Relief valves are rated in

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

15: The 4 basic methods of determining whether the proper amount of refrigerant is being introduced into the system are

  • Buss-eye, weight, pressure, and frost line
  • sight glass, weight, paper method, and frost line.
  • sight glass, weight, pressure, and dipstick
  • sight glass, weight, pressure, and frost line

16: A secondary coolant is defined as

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

17: One watt of electrical energy in a resistive heater will provide _____ BTU/hr

  • 3.415
  • 16.64
  • 34.15
  • 6.830

18: Pressure vessels shall be provided with ___________in accordance with Section VIII of the ASME Boiler & Pressure Vessel Code

  • over pressure protection
  • Pressure vessels need no type of protection as long as it is hydrostatically tested every three months
  • over pressure protection and a rupture disc
  • over pressure protection as well as a temperature protection device

19: Before replacing a seized compressor, the _______ should be determinded.

  • type of refrigerant
  • current draw
  • cause of seizure
  • designed head pressure

20: 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

21: R-12 is

  • dichloromethane
  • trichlorofluoromethane
  • dichlorodifluoromethane
  • dichlorofluoromethane

22: Which occupancy can ammonia be used in?

  • commercial
  • depends on the quantity of freon
  • redifential
  • industrial

23: What is considered a cooling agent?

  • any liquid used for the transmission of heat without vaporization
  • any liquid used for the transmission of heat when vaporization occurs
  • any liquid used for the transmission of heat without condensation
  • any liquid used for the transmission of heat when condensation occur

24: Capacity control on an absorption system is typically accomplished by varying the

  • rate at which heat is supplied to the generator
  • speed of the chilled water circulatory pump
  • speed of the condenser water circulator pump
  • pressure setting on the system's rupture disc

25: When should a relief valve start to function?

  • Before the purge station discharges
  • At it's set pressure
  • 10 psi before it's set pressure
  • Two times it's working pressure