Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
58F
70F
32F
77F
2: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of
2.5 times the design pressure
the aggregate of the high side and low side
the high side
the low side
3: The purpose of a receiver is
a vessel to store refrigerant outside the system
to increase the capacity that the system can hold
to use a a later date
all of the above
4: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
high side of the system
low side of the system
the liquid side of the system
the vapor side of the system
5: 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
6: Can ammonia be used on domestic system?
no, unless there is proper ventilation system installed
yes
yes, for systems under 10 tons
no
7: What is the state of the refrigerant leaving the evaporator?
low temperature superheated vapor
a low temperature subcooled liquid
a high temperature superheated vapor
a high temperature subcooled liquid
8: What is the boiling point of refrigerant governed by?
P&T relationship
Compressor RPM's
Condenser sub-cooling
Evaporator temperature
9: Pressure vessel having an inside diameter exceeding 6” with an internal pressure greater than 15psig shall be marked directly on or on the nameplate the letters _______________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
“U” or “UM”
“UV”
“UM” and “UV”
“UL”
10: R-123 belongs to Group
B-1
B-2
A-3
B-3
11: How would you know if there was a loss of crankcase pressure?
oil will foam
oil level will rise
oil will thin out
oil will thicken
12: Megaohm meter's main function is
to detect weak motor winding insulation of a refrigeration or air conditioning compressor by creating high DC voltages to the compressor
to detect very high resistances to ground of refrigeration or air conditioning compressors
to test very high value capacitors for large 3-phase refrigeration compressors and blower motors.
Both a and b are correct
13: Dual-pressure relief devices should be installed on
vessels of 10 cubic feet or less
vessels of 10 cubic feet or more
vessels of 3 cubic feet or less
vessels of 3 cubic feet or more
14: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
low head pressure
oil in evaporator
not enough oil in the system
moisture in the system
15: Which refrigerant was still able to be vented to the atmosphere after July 1, 1992?
R-22
R-113
R-11
R-12
16: A 24 volt transformer with a 240 volt primary can handle how many amps?
20 amps
10 amps
24 amps
There isn't enough information to answer.
17: Industrial occupancy is
a premise or that portion of a premise that is not open to the public, where access by authorized persons is controlled, and that is used to manufacture, process, or store goods, such as chemicals, food, ice, meat, or petroleum.
is a premise or that portion of a premise where large number of people congregate and from which occupants cannot quickly vacate the space.
a premise or that portion of a premise where people transact business, receive personal service, or purchase food and other goods.
Both a and b are correct
18: Refrigerant systems containing Group I refrigerants can be installed in or on public stairways.
True
False
19: When using nitrogen for brazing, the pressure should be:
125 psig
50-100 psig
Slightly below atmospheric
Very low
20: Which of the following is an inorganic refrigerant?
R-22
Ammonia
Chlorofluorocarbons
All of the above
21: Which winding have the most turns?
Start
run
they have equal amount of turns
depends on the motor phase
22: Most CFC's are
inert but toxic
toxic
flammable
inert
23: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
pick-up voltage
lift voltage
run voltage
boost voltage
24: The color code of a tank of ammonia is
silver
lavender
light green
white
25: A water regulating valve opens when
the compressor is on
when the power is on
when the power is on there is an overcharge of refrigerant