Refrigeration RT/RC Prep Quiz

Topics: All categories in the pool

Quiz Result Settings

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

  • watts
  • voltage
  • amperage
  • reactance

2: one BTU equals

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

3: Evaporators within 18" of a heating coil must be equipped with a

  • pressure relief device
  • low limit control
  • zone valve
  • high limit control

4: Heat that changes the physical state of a substance without effecting a change in its temperature is known as

  • specific heat
  • sensible heat
  • lost heat
  • latent heat

5: Brazed joints melt at temperatures above

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

6: A machine room with a refrigerant system using ammonia shall

  • be provided with a continuously operated ventilation system
  • be considered a non-hazardous location in accordance with National Electrical code
  • have no flame producing apparatus permanently installed and operated
  • All of the above

7: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig

  • 365 psig
  • 327 psig
  • 255 psig
  • 125 psig

8: At higher altitudes, boiling temperatures

  • increase
  • are unaffected
  • depends on the refrigerant
  • decrease

9: The difference between saturated liquid and saturated vapor is

  • temperature
  • pressure
  • heat
  • volume

10: Pressure vessels with an internal volume of 3 cubic feet or less

  • do not need pressure relief protection
  • shall use pressure relief devices
  • shall use fusible plugs
  • shall use pressure relief devices or fusible plugs

11: A secondary coolant is defined as

  • 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
  • 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.

12: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.

  • the same
  • lower
  • higher
  • there is no Group B1 refrigerants

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

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

14: When can recovered refrigerants be reused?

  • They can't
  • Only when used in original owner's equipment
  • Only if used in 30 days of recovery
  • None of the above

15: 1 HP = ____ Watts?

  • 3.1416
  • 11,239
  • 746
  • 3,412

16: Which is considered the more efficient condenser?

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

17: On a single phase motor, when does the start winding cut out?

  • 100% of its RLA speed
  • 25% of its RLA speed
  • 50% of its RLA speed
  • 75% of its RLA speed

18: Halogen refrigerants are corrosive to which type of metal?

  • copper
  • black iron
  • stainless steel
  • magnesium

19: If a condenser is on a roof and the temperature is 35F and dropping the capacity

  • increases
  • decreases
  • run as designed with low ambient controls
  • doesn't change

20: System design pressures must take into consideration, not only, pressures found during normal operation but also what?

  • When it's cold out
  • When there is a malfunction on the high side
  • When its warm out
  • All of the above

21: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?

  • 104 ohms
  • 71 ohms
  • 27 ohms
  • 80 ohms

22: The critical temperature of a refrigerant gas occurs when

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

23: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit

  • 977.6 watts
  • 9,776 watts
  • .9776 watts
  • 9.776 watts

24: A 3-cubic foot receiver must have what type of relief valve?

  • fusible plug
  • relief valve
  • rupture device
  • none of the above

25: Low ambient controls are used when

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