Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: What is the state of the refrigerant leaving the evaporator?
a high temperature subcooled liquid
a low temperature subcooled liquid
a high temperature superheated vapor
low temperature superheated vapor
2: What must be done if refrigeration lines pass through a concrete floor?
leak checked
insulated
moisture barrier
installed through a pipe casing
3: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.
48
18
36
24
4: A pressure vessel having an inside diameter of 6” or less shall be sufficient to withstand ____times the pressure of the saturation temperature of the refrigerant or ____times the critical pressure of the refrigerant, whichever is less.
3.0, 3.5
2.5, 3.0
2.5, 2.5
6.6, 6.6
5: After setting up a forward curved fan for the desired conditions, something happened to lower the total static pressure the fan had to operate against. Which would occur?
CFM and HP decrease
CFM and RPM decrease
CFM and HP increase
RPM and CFM increase
6: When should a relief valve start to function?
10 psi before it's set pressure
Before the purge station discharges
Two times it's working pressure
At it's set pressure
7: Which of the following most closely represents the concentration of Li-Br in a absorption system?
40% Li-Br, 60% distilled water
50% Li-Br, 50% tap water
40% Li-Br, 60% tap water
60% Li-Br, 40% distilled water
8: The pressure relief device of a positive displacement compressor shall discharge in the ______________or in accordance with 9.7.8
low side of the system
the liquid side of the system
high side of the system
the vapor side of the system
9: An example of an "Expendable Refrigerant" is
ammonia
liquid oxygen
lithium bromide
liquid nitrogen
10: Evaporators located ____inches of a heating coil shall be equipped whit a pressure relief device.
18
24
15
10
11: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.
critical pressure
low pressure
design pressure
high pressure
12: one BTU equals
3.41 hp
Pi
12,000 hp
31.4 hp
13: The maximum permissible amperage draw for a 40VA transfomer with a secondary voltage of 24V is
1.7
.1
1.2
.8
14: The generator shell contains the
condenser and the generator
evaporator and the absorber
condenser, the evaporator, and the generator
condenser and the absorber
15: When testing systems using non-positive displacement compressors, the entire system shall be considered for test purposes as the low side.
True
False
16: An oil pressure safety switch should be set at
10-15 psi above low side pressure
5 to 10 psi below low side pressure
10 to 15 psi below low side pressure
5 to 10 psi above low side pressure
17: On a 460V motor, what is he MAXIMUM voltage that can be safely applied to it?
506v
550v
660v
None of the above
18: When a refrigerating machinery room is used, the emergency procedures shall be posted
outside the room, immediately adjacent to each door
on a conspicuous card located near the evaporator
inside the room, immediately adjacent to each door
on a conspicuous card located near the compressor
19: Walls and doors of a machinery room shall be at least _____ hour(s) fire rated.
5
1
3
2
20: Humidity can be sensed with
thermometer
pressure bellows
human hair
bimetal
21: Which creates more of a heat load?
50% RH
90% RH
30% RH
70% RH
22: The actual expansion curve of compressor follows most nearly which one of the following
Adiabatic
Pressure-Temperature
Volume
Isothermal
23: 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
24: Oils, classified as to source, are
animal, vegetable, and castor
naphthalene, mixed, and paraffin
animal, vegetable, and mineral
naphthalene, paraffin, and castor
25: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to