Topics: All categories in the pool
1: Clearance volume
- has no effect on compressor capacity
- is the same on all compressors
- varies depending on compressor speed
- affects compressor capacity
2: What is NOT a positive displacement compressor.
- Scroll
- Rotary
- Centrifugal
- Reciprocating
3: Excessive head pressure is often caused by
- insufficient refrigerant
- air cooled condenser is plugged
- leaking reed valve on the discharge side
- thermostat set too high
4: Increasing superheat will do what to your system?
- Decrease liquid flow
- Increase gas flow
- Increase liquid flow
- Nothing
5: Which of the following is not an air velocity meter?
- Hydrometer
- Anemometer
- Velometer
- Anemotherm
6: What instrument is used to measure very high resistance?
- voltmeter
- ammeter
- meg ohmmeter
- tape measure
7: The principle used in continuous type absorption systems is
- Charles's Law
- Dalton's Law
- Ohm's Law
- Boyle's Law
8: Name a CFC refrigerant(s):
- R-11
- R-12
- R-123
- both a & b
9: How are a compressor and condenser fan wired?
- series
- series-parallel
- parallel-series
- parallel
10: What chemical in the refrigerant set off the leak detection alarm?
- Fluorine
- Chlorine
- Both A and B
- none of the above
11: Foaming of oil in a compressor is most likely to occur
- when ambient temperature are low
- at start-up
- when there is insufficient air across the condenser(i.e., dirty coil)
- when the evaporator temperatures are below 32F
12: Heat cannot of itself, pass from a
- cold to a warmer body
- warm to a colder body
- state of hot energy to a state of cold energy
- None of the above
13: How would you know if there was a loss of crankcase pressure?
- oil will thicken
- oil will foam
- oil will thin out
- oil level will rise
14: The absorber shell contains the
- condenser, the evaporator, and the generator
- condenser and the absorber
- condenser and the generator
- evaporator and the absorber
15: Which of the following is a drop-in for R-22
- R-410A
- R-134A
- R407C
- None of the above
16: In a system designed for sub-zero ambient temperatures, what must be added?
- Infrared dye for leak identification
- Low-ambient kit
- Booster compressor
- Nitrogen
17: What is an example of institutional occupancy?
- Hospital
- Dorms
- Shopping mall
- Football stadium
18: 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
19: Ammonia systems use ____ pressure to adjust oil pressure
- discharge
- air
- liquid
- stream
20: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
- 977.6 watts
- .9776 watts
- 9,776 watts
- 9.776 watts
21: The heat picked up in the evaporator must equal to
- the heat of compression
- the heat lost by the medium being cooled
- the heat gained by the condenser
- the heat giving by the condenser
22: An electronic bridge circuit is basically a
- 24 volt control circuit
- high voltage circuit
- Wheatstone
- suspension
23: What kind of system uses two different refrigerants in separate systems dependent on each other?
- Simple
- Cascade
- R-414B
- Low pressure
24: Liquid line filter-driers on a 410A system must be rated for no less than
- 400 psig
- 600 psig
- 1000 psig
- 200 psig
25: What is a megaohm meter?
- Is an electric meter that measures extremely low resistance valves by sending high DC voltage signal into the object being tested.
- 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