Topics: All categories in the pool
1: Which refrigerant is lighter than air?
- R-11
- R-717
- R-123
- R-134a
2: What is absolute humidity?
- the amount of moisture in the air per one pound of 50% RH air
- the amount of moisture in the air in grains of cubic feet of volume
- the amount of moisture in the air in grains of square feet of volume
- none of the above
3: On a pumpdown system, the liquid-line solenoid is controlled by the
- low-ambient controller
- low pressure switch
- defrost timer
- thermostat
4: "P" represents ______ in the Watt's law formula
- amperage
- watts
- voltage
- reactance
5: 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
- 600 watts
- 1000 watts
6: Total heat of a substance is considered
- empathetical
- sensible heat
- enthalpy
- specific heat
7: What do you need to do when you install a new system?
- Add refrigerant
- Document the superheat and subcooling reading
- Insulate the suction line before you take a superheat reading
- Have it inspected
8: Field Inspections of refrigeration and A/C systems in Massachusetts shall be made by
- District Engineering Inspectors
- Commissioned Inspectors
- Master licensed Technician
- both a or b
9: How are a compressor and condenser fan wired?
- parallel-series
- series
- parallel
- series-parallel
10: The boiling point of a refrigerant is based on
- Temperature
- Heat content
- a pressure-temperature relationship
- None of the above.
11: What is the typical air conditioning operating pressures for R-22?
- 60 psi suction 210 psi discharge
- 25 psi suction 125 psi discharge
- 105 psi suction 340 psi discharge
- None of the above
12: 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
13: What is the refrigerant dichlorodifluoromethane?
- R-134A
- R-12
- R-123
- R-22
14: How many different groups of refrigerants are there?
- 3
- 15
- 7
- 11
15: Transformers are rated in
- volts
- volt-amps
- amps
- volts-ohms
16: The dial of a pressure gauge, when installed on the high side of a system be graduated 1.2 times the designed pressure.
- True
- False
17: A premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space such as auditoriums, ballrooms, classrooms, passenger depots, restaurants, and theaters is considered a(n)
- commercial occupancy
- institutional occupancy
- illegal occupancy
- public assembly occupancy
18: Which is considered the more efficient condenser?
- water cooled
- fan cooled
- air cooled
- spray cooled
19: In an A/C unit, dirty filters will cause
- high discharge pressure
- low suction pressure
- high suction pressur
- low oil pressure
20: R-11 has the greatest corrosive effect on
- Magnesium
- Copper
- Bronze
- Aluminum
21: 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
22: A movie theater would be considered a
- commercial occupancy
- mixed occupancy
- public assembly occupancy
- institutional occupancy
23: Excessive head pressure is often caused by
- thermostat set too high
- leaking reed valve on the discharge side
- insufficient refrigerant
- air cooled condenser is plugged
24: What is the maximum voltage range allowed on an electrical circuit?
- 20%
- 15%
- 5%
- 10%
25: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
- oil in evaporator
- moisture in the system
- low head pressure
- not enough oil in the system