Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: R-22 is classified as a ____ refrigerant on the safety matrix.
B-1
A-2
B-2
A-1
2: The actual expansion curve of compression follows most nearly which one of the following curves?
Pressure Temperature
Adiabatic
Isothermal
Volume Temperature
3: In an air conditioning system, the unit of total heat energy content in an air/vapor mixture is
Enthalpy
Specific heat
Latent heat
Sensible heat
4: A chilled water pump's suction gauge reads 10 psig. The discharge gauge reads 48 psig. What is the head in feet the pump is working against?
88
58
96
38
5: The actual expansion curve of compressor follows most nearly which one of the following
Adiabatic
Isothermal
Volume
Pressure-Temperature
6: In a motor, an internal overload might open if
there's a direct short
there's an open start winding
there's an excess current draw through the motor
there was a high pressure refrigerant was used for a low pressure system.
7: "I" represents _______ in the Watt's law formula.
amperage
voltage
watts
reactance
8: In designing duct work, pressure and ______ need to be considered
length
CFM
duct sealant used
all of the above
9: Which oil is hydoscopic?
animal
polyolester
SW30
mineral
10: A High-Probability System
is such that a leak of refrigerant from a failed connection will enter the occupied space
is a system highly likely to leak form a failed connection or component of such system
is such that any leak will cause injury or death to anyone within a 100 square foot area
is such that a leak of refrigerant from a failed connection will enter an unoccupied space
11: What type of refrigerants are NOT flammable?
CHC
HFC
HCFC
All of the above
12: What type of fuses must be used on a HVAC system?
TR Type, Duel Element, Time Delay
Fast blow
10% lower than RLA
none of the above
13: Lithium-bromide, Li-Br, is best characterized as a
sand
soil
sugar
salt
14: It shall be the duty of the person in charge of the premises on which a refrigeration system containing more than ___ lbs of refrigerant is installed to provide a schematic drawing or panel giving directions for the operation of the system.
55
15
75
50
15: 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, 2.5
2.5, 3.0
6.6, 6.6
16: How do you find net oil pressure on a compressor?
discharge pressure - suction pressure
gross oil pressure - suction pressure
gross oil pressure - discharge pressure
all of the above
17: 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 increase
CFM and HP decrease
CFM and RPM decrease
RPM and CFM increase
18: Which refrigerant is lighter than air?
R-717
R-123
R-11
R-134a
19: 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
20: What would be the classification of a church?
Large mercantile
Institutional
Industrial
Place of assembly
21: Can a R22 line set be reused for a 410A system and if it can be reused, what must be done to it?
Flush with ammonia
Flush with RX-11
Flush with R-718
Flush with R-11
22: When an A/C system is excessively low on refrigerant
it can become contaminated with water
there can be nuisance trip outs
the suction line may be too hot to touch
All of the above
23: Pressure vessels shall be provided with ___________in accordance with Section VIII of the ASME Boiler & Pressure Vessel Code
over pressure protection as well as a temperature protection device
over pressure protection
Pressure vessels need no type of protection as long as it is hydrostatically tested every three months
over pressure protection and a rupture disc
24: The ____ design is the maximum pressure for which a specific part of a refrigeration system is designed.