Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: When a pressure gauge is permanently installed on a system, it must be ___ times the design pressure of the system.
1.2
1
2.2
1.5
2: If the spring is adjusted to increase the superheat, this new setting will
allow more liquid into the evaporator
lengthen the frost line
have no effect on the frost line
shorten the frost line
3: Where must a refrigeration contractor's license number be displayed?
Trucks, license plates, and uniforms
Trucks, invoices, and advertising
Uniforms, checks, and invoices.
Truck, office, every job, and on all equipment
4: An example of direct system is
rooftop unit
chiller
absorber
none of the above
5: When is the only time you can leave a service container attached to a system?
Leaking system
Recovery
Charging
Both b and c
6: Which of the following most closely represents the concentration of Li-Br in a absorption system?
40% Li-Br, 60% tap water
50% Li-Br, 50% tap water
40% Li-Br, 60% distilled water
60% Li-Br, 40% distilled water
7: What is the purpose of a surge capacitor on a contactor?
to balance the sine waves
to keep the contactor pulled in
to protect low voltage equipment
to provide smoother start/stops
8: A positive displacement compressor is
a compressor in which the increase in pressure is attained by changing the internal pressure of the compression chamber
a compressor in which the increase in pressure is attained by changing the internal volume of the compression chamber
is a reciprocating type compressor with 2 or more pistons
where the compressor's suction pressure and the compressor;s discharge pressure is more than 50 PSI
9: Copper and its alloys shall not be used with ammonia
True
False
10: In a properly balanced system with valves open and properly adjusted, if the suction line is warm to the touch, its because of
oil in evaporator
moisture in the system
low head pressure
not enough oil in the system
11: 1 HP = ____ Watts?
3,412
746
11,239
3.1416
12: A 24 volt transformer with a 240 volt primary can handle how many amps?
10 amps
There isn't enough information to answer.
24 amps
20 amps
13: Lithium-bromide, Li-Br, is best characterized as a
sand
salt
sugar
soil
14: The instrument used to measure the specific gravity of absorption chiller solutions is the
Psychrometer
anemometer
refractometer
hydrometer
15: A class A3 refrigerant is considered
non-toxic but highly flammable
toxic and non-flammable
toxic and somewhat flammable
non-toxic and non-flammable
16: Liquid shall not occupy more than ____ of the volume when the temperature of the refrigerant is 90F.
100%
90%
75%
80%
17: 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
run voltage
lift voltage
boost voltage
pick-up voltage
18: Transformers are rated in
volts
amps
volts-ohms
volt-amps
19: Watt's Law indicates Volts X Amps = _________.
Ohms
Current
Watts
Resistance
20: Instead of using a compressor, an absorption air-conditioning chiller uses which of the following as its driving force?
Oil
Electricity
Air
Heat
21: A class B2 refrigerant is considered
toxic and somewhat flammable
non-toxic and non-flammable
non-toxic and highly flammable
toxic and non-flammable
22: What was the main reason for enacting the no venting rule of July 1, 1992?
Ozone depletion
Green house effect
Global warming potential
All of the above
23: What is the minimum height refrigeration piping should be placed against walls?
6'
Ceiling height
72"
7.25'
24: Two systems using separate refrigerants that are superimposed upon one another is called
cascade
booster
indirect
single stage
25: A run capacitor is wired in series with the _____ windings.