Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: 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.
110
100
90
80
2: What device measures the specific gravity of a substance?
Thermometer
Manometer
Hygrometer
Hydrometer
3: What is specific heat?
measured heat
heat required to raise the temperature of 1lb of a substance 1 degree
the specific heat required to change the state of one cubic foot of air to steam
none of the above
4: What type of relief valve is used on low pressure centrifugal compressor systems?
Spring-loaded relief valve
Rupture disc
Purge relief
None of the above
5: What type of oil is used in R-410A systems?
polyolester (POE)
naphthene
mineral oil
polyalkylene glycol (PAG)
6: If the spring is adjusted to increase the superheat, this new setting will
lengthen the frost line
shorten the frost line
have no effect on the frost line
allow more liquid into the evaporator
7: What does safe access mean?
OSHA approved
Well-lit exit signs
Locked doors
A clear unobstructed path to the equipment and controls
8: Machinery rooms must be vented to ______?
basement
outdoors
neutralizing tank
unoccupied spaces
9: The normal operating evaporator temperature of R-410A for air conditioning is typically
45F
158F
32F
155F
10: Capacitors are rated in
megaohms
volt - amperes
micro-farads
kelvins
11: A professional or office building would be considered what type of occupancy?
business
public assembly
commercial
mercantile
12: A compressor that increases vapor pressure by changing the internal volume of the compression chamber is called?
Non-positive displacement
Pressure induced displacement.
Low Pressure displacement
Positive displacement
13: Which refrigerant class listed below is the most flammable?
A3
B2
C3
A2
14: Which refrigerant class listed below is the most flammable?
A-1
B-2
C-3
A-3
15: Halogen refrigerants are corrosive to which type of metal?
copper
stainless steel
magnesium
black iron
16: If a refrigerant leaving the condenser is 94F and the condensing temperature is 105F, the subcooling is
11F
21F
9F
29F
17: Insurance companies shall forward each inspection report of all refrigeration or A/C systems to the Chief of Inspections within
30 days
1 week
14 days
2 months
18: Doors communicating with outside from a mechanical room must be?
Self-closing, wooden, fire door
Self-closing, aligned, fire door
Self-closing, approved, fire door
Steel, approved, weather-stripped
19: A declaration test is needed when the system contains more than
120 lbs
110 lbs
55 lbs
65 lbs
20: A high side float is a
float type valve that controls the crankcase oil level
metering device used on critically charged systems that controls the level of the liquid refrigerant in the high pressure side of the system.
float type valve that controls the amount of refrigerant stored in the receiver
float type switch that stops the compressor when the pressure on the high side becomes too high
21: Group A2 refrigerants have a ______ toxicity rating than Group B1 refrigerants.
lower
there is no Group B1 refrigerants
higher
the same
22: 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.
“U” or “UM”
“UM” and “UV”
“UL”
“UV”
23: When liquid receivers are used, the liquid refrigerant shall not exceed _______percent of the volume at 90F.
99%
80%
75%
90%
24: What is the voltage of each leg of a 480 Volt three-phase motor?
240v
277v
120v
208v
25: The solution that leaves the concentrator in an absorption chiller is referred to as the