Topics: All categories in the pool
1: Ammonia systems use ____ pressure to adjust oil pressure
- stream
- liquid
- discharge
- air
2: Fusible plugs shall not be used with pressure vessels of
- 3 cubic feet or more
- 3 cubic feet or less
- 15 cubic feet or more
- 15 square feet or less
3: On a 460V motor, what is he MAXIMUM voltage that can be safely applied to it?
- 506v
- 550v
- 660v
- None of the above
4: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to
- liquid line that is too small
- shortage of refrigerant
- liquid line that had too high vertical lift
- All of the above
5: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
- run voltage
- pick up voltage
- lift voltage
- boost voltage
6: The critical temperature of a refrigerant gas occurs when
- any decrease in pressure will cause condensation
- the gas returns to a liquid
- any increase in pressure will not liquefy the gas
- the gas is no longer saturated
7: Systems containing more than 110 pounds must have stop valves located at the
- compressor suction inlet
- compressor discharge outlet
- receiver inlet and outlet
- All of the above
8: What device removes the start winding from the circuit of a split-phase motor once the motor reaches 75% of its rated load amps (RLA)?
- motor starter
- centrifugal switch
- printed circuit board (PCB)
- duel-voltage switch
9: What is used to check very low air pressures in air conditioning duct?
- Barometer
- Vacuum gauge
- Manometer
- Anemomter
10: Doors communicating with outside from a mechanical room must be?
- Steel, approved, weather-stripped
- Self-closing, aligned, fire door
- Self-closing, approved, fire door
- Self-closing, wooden, fire door
11: The location of the thermal bulb for the TXV on the evaporator effects
- both the pressure and temperature in the feeler bulb
- the amount of superheat required to operate the TXV
- the amount of liquid in the evaporator
- the amount of gas in the evaporator
12: The main purpose of the accumulator is to
- prevent liquid slugs at the compressor
- store liquid refrigerant
- provide space for the accumulation of oil and containminants
- provide space for vapor to accumulate
13: One ton of refrigeration is defined as ______ btu/minute.
- 200
- 60
- 720,000
- 12,000
14: A premise where large numbers of people congregate and from which occupants can not quickly vacate the space is considered
- commercial occupancy
- public assembly occupancy
- institutional occupancy
- mixed occupancy
15: What is a megaohm meter?
- An electric meter that measures very high resistance values by sending a high DC voltage signal into the object being tested
- An electric meter that measures very high resistance values by sending a low voltage AC signal into the object being tested
- An electric meter used by electricians to test large 3-phase blower motors for the correct rotation
- Is an electric meter that measures extremely low resistance valves by sending high DC voltage signal into the object being tested.
16: When releasing a hydrogenated hydrocarbon refrigerant to the atmosphere, ample ventilation must be provided and
- no flames shall be permitted
- explosion precautions must be taken
- gas masks must be worn
- the owner shall be informed
17: Ammonia belongs to Group
- B-2
- A-2
- B-1
- A-1
18: Ammonia can come in contact with _______ ?
- Brass
- Aluminum
- Copper tubing
- Copper
19: "E" represents _____ in the Watt's law formula.
- reactance
- watts
- voltage
- amperage
20: What is Trichlorotrifluoromethane?
- R-12
- R-113
- R-13
- R-11
21: A 24 volt transformer with a 240 volt primary can handle how many amps?
- 24 amps
- 20 amps
- 10 amps
- There isn't enough information to answer.
22: Name a reason that does not cause reduced condenser air quantity
- High ambient temperature
- Dirty fan blades
- Dirty Coil
- Prevailing winds
23: Thermodynamics is the branch of science that deals with
- energy due to motion
- molecular therory
- heat energy
- state of energy
24: On a day with low relative humidity, the two thermometers on a sling psychrometer will read
- nearly the same
- 2F difference
- a ling psychrometer doesn't have two theremometers.
- far apart or greater difference
25: Single compound Refrigerants are classified by what two criteria?
- Temperature range and hazardousness
- Flammability and toxicity
- Weight and color
- Flammability and temperature range