Topics: All categories in the pool
1: Capacitors are rated in
- micro-farads
- volt - amperes
- megaohms
- kelvins
2: Single compound Refrigerants are classified by what two criteria?
- Flammability and temperature range
- Weight and color
- Flammability and toxicity
- Temperature range and hazardousness
3: On a pumpdown system, the liquid-line solenoid is controlled by the
- low-ambient controller
- thermostat
- defrost timer
- low pressure switch
4: Indirect systems using Group II refrigerants
- shall have all refrigerant containing parts except piping, installed in a Class T machine room
- shall be used for mechanical equipment only
- shall be used in refrigeration system in excess of 1,000 lbs
- shall be used in refrigeration system less than 1,000 lbs
5: Which refrigerant class listed below is the most flammable?
- C3
- B2
- A2
- A3
6: What refrigerant has zero ozone depletion
- HFC
- CFC
- HCFC
- None of the above
7: "I" represents ____ in the Ohm's law formula.
- capacitance
- amperage
- resistance
- voltage.
8: _____ alloys shall not be used in contact with an halogenated refrigerants.
- Magnesium
- Nickel
- Copper
- Zinc
9: An air conditioning system rated for 36,000 BTU's is equivalent to
- two tons of cooling
- 12,000 tons of cooling
- three tons of cooling
- one ton of cooling
10: Which is the lowest vacuum?
- 1,000 Microns
- 5 psig
- 5" hg
- 10 psia
11: What is a high-side float?
- Located in the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the low side of the chiller
- Located in the liquid line entering the evaporator, is a float-type metering device that rises to reduce refrigerant flow when the liquid refrigerant level rises in the high side of the chiller
- An electronic-type metering device that contains a float assembly within the device which can accurately meter refrigerant into the evaporator as the load varies
- Located in the liquid line entering the evaporator, so when the refrigerant level is higher in the liquid line than the evaporator, the float rises to allow more refrigerant flow into the evaporator
12: Clearance volume
- varies depending on compressor speed
- affects compressor capacity
- has no effect on compressor capacity
- is the same on all compressors
13: Liquid level gauge glasses shall have automatic closing shut off valves, except Bull's eye or reflex type.
- True
- False
14: What is a Category "D" fluid?
- Any fluid that exceeds 150 psig and has design temperature of over 366F
- A fluid which is nonflammable, nontoxic, not damaging to human tissues, does not exceed 150 psig, and design temperature is between -20F to 366F
- A toxic fluid, which can produce serious irreversible harm to persons on breathing or bodily contact
- A typical refrigerant used on newer air conditioning and heat pump ssytems
15: Which of the following is not an air velocity meter?
- Anemometer
- Velometer
- Anemotherm
- Hydrometer
16: How many gallons of water do you need per pound of ammonia?
- 10
- 50
- 100
- 1
17: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
- 2.2
- 1.2
- 1.5
- 1
18: Liquid level gauges must be provided with what?
- A low level mark
- A red line
- Automatic shut-offs
- A relief valve
19: If two 500 ohm resistors are connected in series, the resistance will be
- 20 ohms
- 200 ohms
- 500 ohms
- 1000 ohms
20: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
- .8
- 1.2
- .1
- 1.7
21: Heat transferred by conduction from one body to another is done
- via liquids
- via radiation
- via solids
- via heat rays
22: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
- methyl chloride
- ammonia
- R-718
- trichlorotrifluoromethane
23: A hissing noise at the expansion valve is a good indication that
- gas is passing thru it
- expansion valve is oversized
- nothing is passing thru
- liquid is passing thru it
24: Total heat of a substance is considered
- enthalpy
- empathetical
- specific heat
- sensible heat
25: A cross charged power element on an expansion valve would normally be used in what temperature range?
- 0F-38F
- -40F to 0F
- 30F to 50F
- -100F to -40F