Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: What is the minimum size wire you can use on a 30 amp circuit?
16 AWG
12 AWG
10 AWG
14 AWG
2: Brazed joints melt at temperatures above
500F
1,200F
1,000F
800F
3: Clearance volume
varies depending on compressor speed
is the same on all compressors
affects compressor capacity
has no effect on compressor capacity
4: Liquid line filter-driers on a 410A system must be rated for no less than
200 psig
1000 psig
600 psig
400 psig
5: 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
6: Refrigeration piping before being buried shall be
leak tested
encased in pipe duct
pressure tested
All of the above
7: A 50 VA control transformer with a 25 volt control output would be rated for _________ amps.
There isn't enough information to answer.
2
2.5
1250
8: The boiling point of a refrigerant is based on
Temperature
Heat content
a pressure-temperature relationship
None of the above.
9: If the power element of an expansion valve should lose its charge the valve would
overfeed the evaporator
underfeed the evaporator
go closed
go open
10: The normal operating evaporator temperature of R-410A for air conditioning is typically
158F
155F
32F
45F
11: Ohm's Law indicates Amps X Resistance = ___________.
Volts
Impedance
Current
Ohms
12: In an A/C unit, dirty filters will cause
low oil pressure
low suction pressure
high suction pressur
high discharge pressure
13: Which of the following is not an air velocity meter?
Anemotherm
Velometer
Hydrometer
Anemometer
14: 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
100
110
80
15: Halogen refrigerants are corrosive to which type of metal?
magnesium
black iron
stainless steel
copper
16: Color is important in oil because
allows you to see into crankcase
it indicates the viscoisty.
it makes sight glasses easy to read
can tell us something about the refining of oil
17: The density of a gas refers to
cubic feet per pound
pounds per square foot
pounds per cubic foot
pounds per absolute pressure
18: If your suction line is warmer than the room temperature, this may indicate
a low charge
below normal superheat
plugged air filter
an over charge
19: Fractionation occurs when
the pressures increase as the heat load increases
when a fraction of refrigerant is added as the full charge
some of the blended refrigerant evaporates or condenses before the rest of the blend
the pressures decreases as the heat load decreases
20: What type of refrigerants are NOT flammable?
CHC
HFC
HCFC
All of the above
21: 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.
“UV”
“UM” and “UV”
“UL”
“U” or “UM”
22: When a receiver is greater than 3 cubic feet but less than 10 cubic feed, what is the minimum relief device required?
fusible plug
relief valve
rupture disc
all of the above
23: What is the amp draw of a 40 VA transformer at 24 volts
1K amps
1,000 amps
106 amps
1.6 amps
24: 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
25: On a 460V motor, what is he MAXIMUM voltage that can be safely applied to it?