Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: How are a compressor and condenser fan wired?
series
parallel
series-parallel
parallel-series
2: The total amount of refrigerant stored in a machinery room in all containers not provided with relief valves shall not exceed
500 lbs
330 lbs
55 lbs
660 lbs
3: The External equalizer of a TXV compensates for
pressure within the system
pressure within the evaporator
pressure drop across the evaporator coil
pressure drop across the condenser coil
4: Halo-carbon refrigerants cannot be used with what material?
Aluminum
Magnesium alloy
Copper
Stainless Steel
5: Pi equals approximately
3.14
3.41
12,000
746
6: What type refrigerant is NOT ozone depleting?
Halon
CFC
HFC
HCFC
7: Dual-pressure relief devices should be installed on
vessels of 3 cubic feet or less
vessels of 3 cubic feet or more
vessels of 10 cubic feet or less
vessels of 10 cubic feet or more
8: Lithium-bromide, Li-Br, is best characterized as a
sugar
salt
sand
soil
9: RPM's of a centrifugal compressor are at approximately?
15,000
30,000
500
10,000
10: Class A refrigerants are considered
toxic
flammable
non-toxic
non-flammable
11: How far from the ground does a relief valve need to be?
Not more than 3' above grade
At least 20' above grade
At least 25' above grade
At least 15' above grade
12: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
9F
29F
21F
11F
13: On a day with low relative humidity, the two thermometers on a sling psychrometer will read
nearly the same
far apart or greater difference
2F difference
a ling psychrometer doesn't have two theremometers.
14: Foaming of oil in a compressor is most likely to occur
at start-up
when ambient temperature are low
when the evaporator temperatures are below 32F
when there is insufficient air across the condenser(i.e., dirty coil)
15: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
90%
75%
99%
80%
16: The dial of a pressure gauge, when installed on the high side of a system be graduated 1.2 times the designed pressure.
True
False
17: 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
18: In designing duct work, pressure and ______ need to be considered
length
CFM
duct sealant used
all of the above
19: The level of voltage caused by back electromagnetic force that opens the contacts of a potential relay in order to take the start capacitor out of the circuit is
pick up voltage
lift voltage
boost voltage
run voltage
20: 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
21: R-718 is rated unlimited for refrigeration quantity contained in a system. Why?
R-718 is not rated unlimited because it's a dangerous refrigerant
Because it's water
Because it's a non-flammable refrigerant
Because it's cheap
22: Joints in refrigeration piping must be _____ before being covered?
Pressurized
Leak tested
Insulated
Inspected
23: The 4 basic methods of determining whether the proper amount of refrigerant is being introduced into the system are
Buss-eye, weight, pressure, and frost line
sight glass, weight, paper method, and frost line.
sight glass, weight, pressure, and frost line
sight glass, weight, pressure, and dipstick
24: Capacity control on a centrifugal compressor is accomplished by the
post-rotational guide vanes
slide vanes
pre-rotational guide vanes
check valves
25: The test pressure applied to the high side of each factory-assembled refrigerating system shall be at least equal to the design pressure of