Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: Clearance volume
affects compressor capacity
has no effect on compressor capacity
varies depending on compressor speed
is the same on all compressors
2: What is the minimum height refrigeration piping should be placed against walls?
6'
72"
7.25'
Ceiling height
3: If a low-pressure chiller has a low-side leak, which of the following will most likely result?
Low head pressure and high suction pressure
High head pressure and low suction pressure
Low suction pressure and low discharge pressure
High suction pressure and high discharge pressure.
4: Where must a refrigeration contractor's license number be displayed?
Trucks, invoices, and advertising
Trucks, license plates, and uniforms
Truck, office, every job, and on all equipment
Uniforms, checks, and invoices.
5: Fusible plugs shall not be used with pressure vessels of
15 square feet or less
3 cubic feet or more
3 cubic feet or less
15 cubic feet or more
6: If the compression ratio on a centrifugal compressor rises too high, the compressor will stop pumping and make a loud sound commonly referred to as a
merge
purge
surge
splurge
7: The gauge thickness required on a CO2 tank construction is
3/32"
1/16"
1/8"
5/16"
8: Dual-pressure relief devices should be installed on
vessels of 10 cubic feet or more
vessels of 3 cubic feet or less
vessels of 3 cubic feet or more
vessels of 10 cubic feet or less
9: Heat cannot of itself, pass from a
cold to a warmer body
warm to a colder body
state of hot energy to a state of cold energy
None of the above
10: A device used to measure small pressure differences is the
manometer
phsycometirc
anemometer
pyrometer
11: When systems are protected by a high pressure relief device, the compressor's pressure limiting device shall be set at or below ____ % of the operating pressure of the high side relief device.
90
80
100
110
12: How many volts would you read on a 480V system phase to phase?
480
277
1/3 the voltage
13: By using nitrogen within a pipe during brazing operation,
Exterior scale formation is minimized
Discoloration is prevented
The explosion hazard is confined
Copper oxide formation is prevented
14: How much clearance do you need around the perimeter of electrical panels?
24"
12"
18"
36"
15: Before you change the type of refrigerant in a refrigeration system, what three things must be done?
you can't change refrigerants
place sign, check for leaks, insulate
nothing must be done
make sure it's compatible, notify owner, notify A.H.J
16: 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)
commercial occupancy
illegal occupancy
public assembly occupancy
institutional occupancy
17: Adjusting the spring pressure on a TXV
adjusts the bulb charge
makes no difference
changes superheat
changes subcooling
18: Direct systems using Group II refrigerants
shall be installed per instruction of the AHJ
shall be allowed to be used for human comfort.
shall be installed in Class T machinery rooms
shall not be used for air condition for human comfort
19: How many refrigerant classifications are there for toxicity?
5
2
1
3
20: R-12 is
dichlorofluoromethane
dichloromethane
trichlorofluoromethane
dichlorodifluoromethane
21: A pressure relief should be located at least _______ from windows and doors.
25'
30'
15'
20'
22: Halogenated refrigerants cannot be used with what material?
Stainless steel
Aluminum
Magnesium alloy
Copper
23: Which of the following controllers would you expect to be most sensitive to temperature changes?
immersion controller
aquastat
low voltage t-stat
line voltage t-stat
24: The principle used in continuous type absorption systems is
Ohm's Law
Charles's Law
Dalton's Law
Boyle's Law
25: The main cause of enacting the "no vending rule" of July 1st 1992 was