Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: The evaporator is a device to
store liquid refrigerant
absorb heat into the refrigeration system
Keep the compressor busy
remove heat from the refrigeration system
2: Systems containing more than 110 pounds must have stop valves located at the
compressor suction inlet
compressor discharge outlet
receiver inlet and outlet
All of the above
3: Which of the following is NOT a positive displacement compressor?
screw
reciprocating
centrifugal
scroll
4: When is the only time you can leave a service container attached to a system?
Leaking system
Recovery
Charging
Both b and c
5: Which refrigerant replaced R-12?
R-22
R-134A
R-410A
R-407A
6: Which of the following most closely represents the concentration of Li-Br in a absorption system?
40% Li-Br, 60% distilled water
60% Li-Br, 40% distilled water
40% Li-Br, 60% tap water
50% Li-Br, 50% tap water
7: Two systems using separate refrigerants that are superimposed upon one another is called
cascade
booster
indirect
single stage
8: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
R-718
ammonia
methyl chloride
trichlorotrifluoromethane
9: A pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
50
25
66
22
10: Cooling tower lowers condenser water temp by
condensation
evaporative cooling
running fans at 100%
running water thru a secondary heat exchanger
11: What do you need to do when you install a new system?
Document the superheat and subcooling reading
Insulate the suction line before you take a superheat reading
Have it inspected
Add refrigerant
12: Which of the following is an example of an azeotropic refrigerant?
R-404A
R-500
R-410A
R-134A
13: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
High head pressure and low suction pressure
High suction pressure and high discharge pressure.
Low suction pressure and low discharge pressure
Low head pressure and high suction pressure
14: What kind of material can't be used on the outlet of a relief valve?
Copper
PVC
Stainless Steel
Aluminum
15: A premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space such as auditoriums, ballrooms, classrooms, passenger depots, restaurants, and theaters is considered a(n)
institutional occupancy
commercial occupancy
illegal occupancy
public assembly occupancy
16: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to
liquid line that is too small
shortage of refrigerant
liquid line that had too high vertical lift
All of the above
17: R-22 is classified as a ____ refrigerant on the safety matrix.
A-1
A-2
B-1
B-2
18: In a system designed for sub-zero ambient temperatures, what must be added?
Booster compressor
Low-ambient kit
Infrared dye for leak identification
Nitrogen
19: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
1.5
1
2.2
1.2
20: The difference between saturated liquid and saturated vapor is
volume
pressure
heat
temperature
21: What happens to copper joints when overheated?
nothing
joint becomes oxidized and ditorted
copper becomes harder
none of the above
22: A cross charged power element on an expansion valve would normally be used in what temperature range?
-40F to 0F
0F-38F
-100F to -40F
30F to 50F
23: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
Solenoid valve
EEV
EPR valve
CPR valve
24: What is the minimum size wire you can use on a 30 amp circuit?