Topics: All categories in the pool
1: Electricity involves the movement of electrons in atoms
- True
- False
2: Fusible plugs shall not be used with pressure vessels of
- 3 cubic feet or less
- 15 square feet or less
- 3 cubic feet or more
- 15 cubic feet or more
3: What is an egress?
- A code violation
- An escape route
- An entrance or exit
- A valve put on the low side of the system to prevent frosting
4: Foaming of oil in a compressor is most likely to occur
- when ambient temperature are low
- when there is insufficient air across the condenser(i.e., dirty coil)
- when the evaporator temperatures are below 32F
- at start-up
5: Three-phase motors have what type of windings?
- one start winding and one run winding.
- three run windings
- three run windings and 3 start windings
- three start windings
6: Excessive head pressure is often caused by
- leaking reed valve on the discharge side
- insufficient refrigerant
- thermostat set too high
- air cooled condenser is plugged
7: While water is evaporated in an evaporative condenser the impurities which were in the water are
- accumulate in the sump water
- blown to the atmosphere by the fan
- remain in the air
- washed out of the air by the spray pump
8: The gauge thickness required on a CO2 tank construction is
- 1/8"
- 3/32"
- 1/16"
- 5/16"
9: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 32F
- 158F
- 155F
- 45F
10: What is not a requirement of a class T machine room?
- self-closing doors
- automatic ventilation
- tight fitting doors
- fire hose connection to the building fire protection system
11: What's the purpose of a megohmmeter?
- To measure low to very low resistance values
- To alternate the current in a DC circuit in order to calculate the total impedance of a circuit
- To measure very high resistances
- None of the above
12: Calculate the voltage in a series circuit when the total amperage is 10 amps and the resistors have values of: R1=12 ohms, R2=8 ohms, R3=4 ohms
- 240 volts
- 2,400 volts
- 24.0 volts
- 2.40 volts
13: The two basic types of evaporators are
- direct expansion and plate
- flooded and direct expansion
- prime surface and finned
- finned and plate
14: What chemical in the refrigerant set off the leak detection alarm?
- Fluorine
- Chlorine
- Both A and B
- none of the above
15: Walls and doors of a machinery room shall be at least _____ hour(s) fire rated.
- 1
- 5
- 3
- 2
16: Pressure vessels with an internal volume of 3 cubic feet or more
- shall use pressure relief devices or fusible plugs
- shall use fusible plugs
- do not need pressure relief protection
- shall use pressure relief devices
17: How many forces operate a thermostatic expansion valve?
- 1
- 3
- 2
- 4
18: R-123 belongs to Group
- B-2
- A-3
- B-3
- B-1
19: What happens to copper joints when overheated?
- nothing
- joint becomes oxidized and ditorted
- copper becomes harder
- none of the above
20: Machinery rooms must be vented to ______?
- outdoors
- unoccupied spaces
- neutralizing tank
- basement
21: What is an example of institutional occupancy?
- Football stadium
- Shopping mall
- Dorms
- Hospital
22: If a condenser is on a roof and the temperature is 35F and dropping the capacity
- increases
- run as designed with low ambient controls
- decreases
- doesn't change
23: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.
- 24
- 48
- 36
- 18
24: When the compressor is below the condensor
- traps are needed on the suction line
- traps are not needed on this type of system
- traps are needed on the oil return line
- traps are needed on the discharge line
25: What device measures the specific gravity of a substance?
- Hygrometer
- Hydrometer
- Thermometer
- Manometer