Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: What is used to check very low air pressures in air conditioning duct?
Vacuum gauge
Anemomter
Barometer
Manometer
2: What do you need to do when you install a new system?
Have it inspected
Document the superheat and subcooling reading
Insulate the suction line before you take a superheat reading
Add refrigerant
3: Which refrigerant class listed below is the most flammable?
C-3
B-2
A-3
A-1
4: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
specific heat
sensible heat
latent heat
lost heat
5: Name three things that must be done when changing refrigeration lubricant?
Place sign, check for leaks, insulate
Nothing must be done
You can't change lubricants.
Make sure it's compatible, notify owner, notify AHJ
6: Class 3 refrigerants are
non-toxic
highly flammable
non-flammable
toxic
7: A check valve is a device
designed to allow the flow of refrigerant gas in both directions
that is always spring loaded
with a pressure drop
found on high pressure steam systems
8: Joints in piping for refrigeration containing parts must withstand temperatures of ___?
600F
800F
1000F
700F
9: What is specific heat?
measured heat
heat required to raise the temperature of 1lb of a substance 1 degree
the specific heat required to change the state of one cubic foot of air to steam
none of the above
10: Pairs of mating stop valves that allow sections of a system to be joined before opening these valves or separated after closing them are
gate or globe valves
companion or block valves
ball valves
king valves
11: R-22 is classified as a ____ refrigerant on the safety matrix.
B-1
B-2
A-2
A-1
12: Sensible heat is the heat added to a substance to
raise its temperature
change its state
cause evaporation
freeze it
13: A split-phase motor has a ______ winding and a ____ winding
run, common
duel-run, duel-start
run, start
start, common
14: Transformers are rated in
amps
volt-amps
volts-ohms
volts
15: What is the minimum size wire you can use on a 30 amp circuit?
14 AWG
12 AWG
10 AWG
16 AWG
16: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
75%
99%
90%
80%
17: Who is permitted to access a refrigeration machine room?
Any employee
Anyone, it's a completely safe area
Contractors only
Authorized persons only
18: Which of the following is NOT a positive displacement compressor?
centrifugal
scroll
screw
reciprocating
19: The most common type of motor starter is
delts-wye starter
across the line starter
duel-winding starter
part winding starter
20: Trichlorofluoromethane is the name of what refrigerant?
R-12
R-113
R-11
R-502
21: What must be done to all doors and access points in duct work going through a mechanical room?
Must be hindged
Must be screwed shut
Must be sealed and gasketed
All of the above
22: Which oil is hydoscopic?
SW30
polyolester
animal
mineral
23: The color code of a tank of ammonia is
silver
light green
white
lavender
24: By using nitrogen within a pipe during brazing operation,
Exterior scale formation is minimized
Discoloration is prevented
Copper oxide formation is prevented
The explosion hazard is confined
25: Materials used in construction and installation materials used in the manufacture or installation of refrigerating equipment shall be suitable for conveying refrigerant and the refrigerant oils and will not deteriorate in the presence of what?