Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

1: The instrument used to measure the specific gravity of absorption chiller solutions is the

  • Psychrometer
  • anemometer
  • refractometer
  • hydrometer

2: Which has more turns in the windings: Start windings or Run windings?

  • Start windings
  • Run windings
  • They both have the exact same turns
  • Depends on the system and capacitor used

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

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

4: How many BTU's is produced by one watt of energy

  • 3.41
  • 3.00
  • 1
  • 2.57

5: 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.

  • 80
  • 100
  • 90
  • 110

6: What should not (and can not) be located between a pressure imposing device and a pressure-limiting device?

  • Muffler
  • Moisture indicator
  • Foot valve
  • Stop valve

7: If a purge unit fails on a low pressure chiller, what are the symptoms?

  • low pressure chillers do not have purge units
  • high head pressure
  • increased capacity
  • low suction pressure

8: What refrigerant doesn't have to be classifted?

  • R-717
  • R-134a
  • R-718
  • R-711

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

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

10: The density of a gas refers to

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

11: What is not a requirement of a Class T machine room?

  • Fire hose connected to the building fire protection system.
  • Tight fitting doors
  • Automatic ventilation
  • Self-closing doors

12: The critical temperature of a refrigerant gas occurs when

  • the gas is no longer saturated
  • any decrease in pressure will cause condensation
  • the gas returns to a liquid
  • any increase in pressure will not liquefy the gas

13: A high side float is a

  • 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.
  • float type switch that stops the compressor when the pressure on the high side becomes too high

14: RPM's of a centrifugal compressor are at approximately?

  • 15,000
  • 10,000
  • 500
  • 30,000

15: Fractionation occurs when

  • when a fraction of refrigerant is added as the full charge
  • some of the blended refrigerant evaporates or condenses before the rest of the blend
  • the pressures decreases as the heat load decreases
  • the pressures increase as the heat load increases

16: A motor is rated for 120 volts and has a RLA (rated-load amps) of 5 amps. What is the wattage of the motor?

  • 5KW
  • 746 watts
  • 1000 watts
  • 600 watts

17: What would be the classification of a church?

  • Industrial
  • Large mercantile
  • Place of assembly
  • Institutional

18: When an inspection is needed, how often must it be done?

  • every 24 months
  • every 18 months
  • annually
  • every 36 months

19: "I" represents ____ in the Ohm's law formula.

  • voltage.
  • resistance
  • capacitance
  • amperage

20: Low ambient controls are used when

  • economizers are used
  • when systems run all year round
  • always
  • on air conditioning systems only

21: Large mercantile occupancy is

  • a premise or that portion of a premise where more than 200 persons congregate on levels above or below street level to purchase personal merchandise
  • a premise of that portion of a premise where more than 50 persons congregate on levels above of below street level to purchase personal merchandise.
  • a premise of that portion of a premise where more than 100 persons congregate on levels above of below street level to purchase personal merchandise.
  • a premise or that portion of a premise where more than 1500 persons congregate on levels above or below street level to purchase personal merchandise

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

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

23: Relief valves are rated in

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

24: Doors communicating with outside from a mechanical room must be?

  • Self-closing, aligned, fire door
  • Self-closing, wooden, fire door
  • Steel, approved, weather-stripped
  • Self-closing, approved, fire door

25: Brazed joints melt at temperatures above

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