Topics: All categories in the pool
1: A micron is
- one millonths of a micrometer
- a larger unit of measurement than Hg
- one thousandths of a millimeter
- one millonths of a centimeter
2: A class B2 refrigerant is considered
- toxic and non-flammable
- toxic and somewhat flammable
- non-toxic and highly flammable
- non-toxic and non-flammable
3: What is used to check very low air pressures in air conditioning duct?
- Barometer
- Anemomter
- Vacuum gauge
- Manometer
4: A class A3 refrigerant is considered
- toxic and non-flammable
- toxic and somewhat flammable
- non-toxic and non-flammable
- non-toxic but highly flammable
5: R-12. R-22, and R-40 are considered Group I refrigerants.
- True
- False
6: When an inspection is needed, how often must it be done?
- every 18 months
- annually
- every 24 months
- every 36 months
7: Which occupancy can ammonia be used in?
- industrial
- commercial
- redifential
- depends on the quantity of freon
8: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- .8
- 1.2
- 1.7
- .1
9: What is an egress?
- A valve put on the low side of the system to prevent frosting
- A code violation
- An entrance or exit
- An escape route
10: Gauge pressure is
- Barometric pressure
- Force of pressure above that of atmosphere
- Absolute pressrue
- Atmospheric pressure
11: A class B1 refrigerant is considered
- non-toxic but highly flammable
- non-toxic and non-flammable
- toxic but non-flammable
- toxic and somewhat flammable
12: The density of a gas refers to
- cubic feet per pound
- pounds per absolute pressure
- pounds per cubic foot
- pounds per square foot
13: What percentage of amperage difference is allowable phase to phase on a HVAC circuit phased to phase?
- 4%
- 1%
- 25%
- 2%
14: R-22 is considered a(n)
- CFC
- HFC
- HCFC
- HCFCH
15: Oils, classified as to source, are
- animal, vegetable, and mineral
- animal, vegetable, and castor
- naphthalene, paraffin, and castor
- naphthalene, mixed, and paraffin
16: Direct systems using Group II refrigerants
- shall be installed per instruction of the AHJ
- shall be installed in Class T machinery rooms
- shall be allowed to be used for human comfort.
- shall not be used for air condition for human comfort
17: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.
- 48
- 36
- 18
- 24
18: What type of voltage causes the winding in a potential relay to open?
- BEMF (Back Electro-Motive Force)
- 24V control voltage from the thermostat
- 120V line voltage
- None of the above
19: Which of the following most closely represents the concentration of Li-Br in a absorption system?
- 40% Li-Br, 60% distilled water
- 60% Li-Br, 40% distilled water
- 40% Li-Br, 60% tap water
- 50% Li-Br, 50% tap water
20: There can be no airflow from an occupied space through a machine room unless what?
- System is high velocity
- System is ducted and sealed
- Duct is not located in the ceiling
- None of the above.
21: Ammonia vaporization takes place at what temperature?
- -32F
- -110F
- -28F
- -460F
22: 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
23: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
- 50
- 22
- 25
- 66
24: A premise where large numbers of people congregate and from which occupants can not quickly vacate the space is considered
- mixed occupancy
- public assembly occupancy
- commercial occupancy
- institutional occupancy
25: In designing duct work, pressure and ______ need to be considered
- length
- CFM
- duct sealant used
- all of the above