Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.
the same
higher
lower
there is no Group B1 refrigerants
2: Copper and its alloys shall not be used with ammonia
True
False
3: What should never be used in pressure testing refrigeration systems?
Oxygen
Compressed air
Nitrogen
Both a and b
4: One atmosphere equals
0 psia
14.7
29.4
0 psig
5: Mercury was used in thermometers primarily because it
was inexpensive
expands uniformly
never freezes
vaporizes at very high temperatures
6: When using nitrogen for brazing, the pressure should be:
125 psig
50-100 psig
Slightly below atmospheric
Very low
7: A mixed occupancy occurs when two or more occupancies are located with the same building
true
false
8: A R-410A system running with a condensing temperature of 110F and 50F evaporator temperature will read pressures of ___ on the high side and ___ on the low side
365 psig, 120 psig
455 psig, 185 psig.
226 psig, 68 psig
257 psig, 77 psig
9: An example of an "Expendable Refrigerant" is
liquid oxygen
liquid nitrogen
lithium bromide
ammonia
10: Watt's Law indicates Volts X Amps = _________.
Watts
Resistance
Ohms
Current
11: Machinery rooms shall be vented to _____________ and utilizing mechanical ventilation.
the return air ducted system
the outdoors
Machinery rooms need not be vented
the mechanical room housing the refrigeration system
12: The critical temperature of a refrigerant gas occurs when
the gas returns to a liquid
the gas is no longer saturated
any increase in pressure will not liquefy the gas
any decrease in pressure will cause condensation
13: Refrigerant is metered into the evaporator on a large centrifugal chiller thru the
low side of the system
high side float assembly
cap tube
none of the above
14: Which oil is hydoscopic?
polyolester
animal
SW30
mineral
15: "I" represents _______ in the Watt's law formula.
reactance
amperage
voltage
watts
16: Heat is a form of
matter
power
work
energy
17: A chilled water pump suction gauge reads 10 psig. Discharge gauge reads 48 psig. The head in feet of the pump is working against
116
108
88
38
18: Pressure-limiting device isn't required on a factory-sealed system containing less than ____ lbs.
50
33
18
22
19: Which of the following types of oils are hygroscopic?
polyolester (POE)
polyalkylene glycol (PAG)
naphthene mineral
both a and b
20: At higher altitudes, boiling temperatures
increase
are unaffected
decrease
depends on the refrigerant
21: What instrument is used to measure very high resistance?
ammeter
meg ohmmeter
tape measure
voltmeter
22: 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
23: R-410A is classified as a ____ refrigerant on the safety matrix.
A-2
B-1
A-1
B-2
24: 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?