Topics: All categories in the pool
1: An electrical circuit has a 208V power supply and draws 47 amps total, What would be the wattage of the circuit
- 9.776 watts
- .9776 watts
- 9,776 watts
- 977.6 watts
2: What type of oil is used in R-410A systems?
- polyalkylene glycol (PAG)
- mineral oil
- naphthene
- polyolester (POE)
3: An azeotropic refrigerant is
- a mixture of two or more refrigerants that boil at about the same temperature minimizing temperature glide.
- a mixture of two or more refrigerants that boil at much different temperatures causing temperature glide
- a mixture of two or more refrigerants that boil at much different temperatures minimizing temperature glide
- none of the above
4: Which is considered the more efficient condenser?
- water cooled
- air cooled
- spray cooled
- fan cooled
5: Which of the following types of oils are hygroscopic?
- polyolester (POE)
- polyalkylene glycol (PAG)
- naphthene mineral
- both a and b
6: In an electrical circuit, what is potential measured in?
- Herys
- Ohms
- Volts
- Amps
7: 746 watts is equal to
- 10 hp
- 1 hp
- Pi
- 100 hp
8: Which of the following is an example of an azeotropic refrigerant?
- R-404A
- R-134A
- R-410A
- R-500
9: Before replacing a seized compressor, the _______ should be determinded.
- type of refrigerant
- current draw
- cause of seizure
- designed head pressure
10: Volts x amps equals
- Ohms Law
- Impedance
- Watts
- Inductance
11: What is the temperature that a liquid and a vapor can exist in equilibrium called?
- Dry bulb temperature
- Critical temperature
- Saturated temperature
- Wet bulb temperature
12: What is the typical air conditioning operating pressures for 410A?
- 60 psi suction, 210 psi discharge
- 25 psi suction, 125 psi discharge
- 105 psi suction, 350 psi discharge
- None of the above
13: A crankcase heater has a supplied voltage of 100 volts and is drawing 1.4 amps. What is the resistance?
- 71 ohms
- 80 ohms
- 104 ohms
- 27 ohms
14: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
15: A machine room with a refrigerant system using ammonia shall
- be provided with a continuously operated ventilation system
- be considered a non-hazardous location in accordance with National Electrical code
- have no flame producing apparatus permanently installed and operated
- All of the above
16: An oil pressure safety switch should be set at
- 5 to 10 psi below low side pressure
- 10 to 15 psi below low side pressure
- 10-15 psi above low side pressure
- 5 to 10 psi above low side pressure
17: Heat transferred by conduction from one body to another is done
- via solids
- via heat rays
- via liquids
- via radiation
18: 14.7 psia is equivalent to
- atmospheric pressure at seal level
- 29.92" Hg
- 0 psig
- All of the above.
19: A hissing noise at the expansion valve is a good indication that
- expansion valve is oversized
- gas is passing thru it
- liquid is passing thru it
- nothing is passing thru
20: What effect does the temperature of air have on humidity?
- warmer air holds more moisture then cooler air
- cooler air holds more moisture then warmer air
- air has no effect of humidity
- none of the above
21: Which of the following is a drop-in for R-22
- R-410A
- R-134A
- R407C
- None of the above
22: A motor is rated for 120 volts and has a RLA (rated-load amps) of 5 amps. What is the wattage of the motor?
- 746 watts
- 600 watts
- 5KW
- 1000 watts
23: 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
24: Methyl Chloride is a halogenated refrigerant and should not come in contact with
- aluminum
- zinc
- magnesium
- all of the above
25: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 158F
- 32F
- 45F
- 155F