Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: Pressure vessels having design pressures of 15 psig or less shall have the strength to withstand at least ______times the design pressure.
5.5
2.0
3.0
2.5
2: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
EEV
CPR valve
Solenoid valve
EPR valve
3: A solder joint melts at temperatures of
less than 400F
1,200F to 1,500F
600F to 900F
400F to 800F
4: The actual expansion curve of compression follows most nearly which one of the following curves?
Pressure Temperature
Isothermal
Adiabatic
Volume Temperature
5: B3 refrigerants are considered
toxic but non-flammable
non-toxic but non-flammable
non-toxic but flammable
toxic and highly flammable
6: 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
7: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
Make sure its compatible, notify owner, and notify AHJ.
you can never change refrigerants
Nothing must be done
Place sign, check for leaks, and insulate suction line
8: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
24
18
10
15
9: On a centrifugal compressor, stationary diffuser vanes are needed to
stop gas flow
increase the clearance space
prevent high pressure on the packing
convert velocity energy to pressure
10: What is the refrigerant dichlorodifluoromethane?
R-123
R-134A
R-22
R-12
11: Copper and its alloys shall not be used with ammonia
True
False
12: When releasing a hydrogenated hydrocarbon refrigerant to the atmosphere, ample ventilation must be provided and
the owner shall be informed
no flames shall be permitted
explosion precautions must be taken
gas masks must be worn
13: Booster compressors connect to the ____ side of the compressor
liquid
oil side
vapor
low side
14: In a system designed for sub-zero ambient temperatures, what must be added?
Infrared dye for leak identification
Booster compressor
Low-ambient kit
Nitrogen
15: The rupture disc on a low-pressure chiller typically releases pressure at
10 psig
5 psig
0 psig
15 psig
16: Where are the three places that the discharge from an ammonia relief valve be piped?
atmosphere, tank containing water, where the A.H.J. indicates
underground, into drain, into mechanical room
to chemical neutralizing tank only
none of the above
17: 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
18: What is absolute humidity?
the amount of moisture in the air per one pound of 50% RH air
the amount of moisture in the air in grains of cubic feet of volume
the amount of moisture in the air in grains of square feet of volume
none of the above
19: Capacitors are rated in
megaohms
volt - amperes
micro-farads
kelvins
20: Three-phase motors have what type of windings?
three run windings
one start winding and one run winding.
three run windings and 3 start windings
three start windings
21: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
77F
58F
70F
32F
22: The outer portion of shell of the compressor used on low-pressure chillers is called the
baffle
nozzle
suction
volute
23: A start capacitor is wired in _____ with the start windings.
series-parallel
parallel
series
junction
24: "I" represents _______ in the Watt's law formula.
watts
reactance
amperage
voltage
25: The main cause of enacting the "no vending rule" of July 1st 1992 was