Topics: All categories in the pool
1: Mercury was used in thermometers primarily because it
- was inexpensive
- vaporizes at very high temperatures
- expands uniformly
- never freezes
2: R-717 is
- trichloromethane
- carbon dioxide
- ammonia
- water
3: The two float-type metering devices are the
- high-side float and the low-side float
- liquid float and the vapor float
- liquid float and the low-side float
- vapor float and the low-side float.
4: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
- place sign, check for leaks, insulate
- you can't change refrigerants
- make sure it's compatible, notify owner, notify A.H.J
- nothing must be done
5: R-718 is rated unlimited for refrigeration quantity contained in a system. Why?
- Because it's cheap
- Because it's water
- Because it's a non-flammable refrigerant
- R-718 is not rated unlimited because it's a dangerous refrigerant
6: E = I X R is
- Ohms Law
- Amps Law
- Watts Law
- Impedance Law
7: Absolute pressure is
- Gauge Pressure
- Atmospheric Pressure
- Gauge + Atmospheric Pressure + Pi
- none of the above
8: Give an example of a secondary coolant?
- R-717
- R-718
- R-410A
- R-12
9: Transformers are rated in
- amps
- volts-ohms
- volt-amps
- volts
10: The low pressure oil safety switch
- resets itself after the time delay has terminated
- resets itself automatically
- never trips
- must be reset manually
11: Where can 50/50 solder be used on?
- suction line
- liquid line
- discharge line
- none of the above
12: Ohm's Law indicates Amps X Resistance = ___________.
- Volts
- Ohms
- Current
- Impedance
13: Two capacitors are wired in parallel. One capacitor has a value of 15uf. The other has a value of 25uf. What is the total value supplied?
- 25 uf
- 15 uf
- 20 uf
- 40 uf
14: Halogenated refrigerants cannot be used with what material?
- Copper
- Stainless steel
- Magnesium alloy
- Aluminum
15: Refrigerant systems containing Group I refrigerants can be installed in or on public stairways.
- True
- False
16: The 4 basic methods of determining whether the proper amount of refrigerant is being introduced into the system are
- sight glass, weight, pressure, and dipstick
- sight glass, weight, paper method, and frost line.
- Buss-eye, weight, pressure, and frost line
- sight glass, weight, pressure, and frost line
17: Pressure is equivalent of
- Force X Area
- Force / Area
- Force
- Area X Force
18: How many groups of refrigerants are there?
- 1
- 7
- 5
- 3
19: The certificate of inspection
- shall be posted on the compressor shell or electrical panel at the unit
- shall be authorized by a notarized insurance company
- shall be $20 and an additional fee of $1 for each tone above 20 tons
- shall be posted and protected from dirt, water, and other elements
20: No open flames are allowed in the machinery room unless?
- Only when combustion air is provided from outside of the machinery room
- Approved by the installing contractor
- Approved by the authorized person
- Never can be allowed
21: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?
- 5 amps
- 10 amps
- 15 amps
- 20 amps
22: A moisture indicator must
- be yellow
- be sight side up
- change color when exposed to moisture
- be filled with liquid
23: Large mercantile occupancy is
- a premise or that portion of a premise where more than 200 persons congregate on levels above or below street level to purchase personal merchandise
- a premise of that portion of a premise where more than 100 persons congregate on levels above of below street level to purchase personal merchandise.
- a premise or that portion of a premise where more than 1500 persons congregate on levels above or below street level to purchase personal merchandise
- a premise of that portion of a premise where more than 50 persons congregate on levels above of below street level to purchase personal merchandise.
24: What type of fuses must be used on a HVAC system?
- TR Type, Duel Element, Time Delay
- Fast blow
- 10% lower than RLA
- none of the above
25: A class B1 refrigerant is considered
- non-toxic but highly flammable
- toxic and somewhat flammable
- toxic but non-flammable
- non-toxic and non-flammable