Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: R-410A can segregate in the system or chemically change its composition due to a leak.
True
False
2: When using nitrogen for brazing, the pressure should be:
50-100 psig
Very low
125 psig
Slightly below atmospheric
3: What is the refrigerant dichlorodifluoromethane?
R-12
R-134A
R-123
R-22
4: A 3-cubic foot receiver must have what type of relief valve?
fusible plug
relief valve
rupture device
none of the above
5: Refrigerants shall be classified by
color codes
maximum permissible quantities of each group
requirements for commercial, industrial, and residential occupancies
toxicity and flammability
6: 1 HP = ____ Watts?
3,412
746
11,239
3.1416
7: A normally operating R-410A system with a condensing temperature of 110F will have a high side pressure of around ______ psig
327 psig
125 psig
255 psig
365 psig
8: What are the three components of a transformer?
Contacts, secondary coil, and core
Primary coil, secondary coil, and core
Primary core, secondary coil, and high and low voltage connectors.
Primary coil, secondary coil, and copper contacts
9: Dual-pressure relief devices should be installed on
vessels of 10 cubic feet or less
vessels of 3 cubic feet or less
vessels of 3 cubic feet or more
vessels of 10 cubic feet or more
10: Adjusting the spring pressure on a TXV
makes no difference
changes subcooling
changes superheat
adjusts the bulb charge
11: What device measures the specific gravity of a substance?
Hydrometer
Manometer
Hygrometer
Thermometer
12: Pressure vessels with an internal volume of 3 cubic feet or more
shall use pressure relief devices
do not need pressure relief protection
shall use pressure relief devices or fusible plugs
shall use fusible plugs
13: The 4 basic methods of determining whether the proper amount of refrigerant is being introduced into the system are
sight glass, weight, pressure, and frost line
sight glass, weight, paper method, and frost line.
Buss-eye, weight, pressure, and frost line
sight glass, weight, pressure, and dipstick
14: How are safety controls wired in a circuit?
Parallel
Either series or parallel
Series/parallel
Series
15: Refrigerant piping crossing an open space that affords passageway in any building shall not be less than _____ feet above the floor unless piping is located against the ceiling.
7.25'
8'4"
7.00'
9.00'
16: Heat is a form of
matter
work
energy
power
17: On a pumpdown system, the liquid-line solenoid is controlled by the
thermostat
low-ambient controller
low pressure switch
defrost timer
18: Absolute pressure is
Gauge Pressure
Atmospheric Pressure
Gauge + Atmospheric Pressure + Pi
none of the above
19: The best way to determine the voltage requirement for an electrical component is to
check with the utility company
read the nameplate data
read the voltage with a mulitmeter
determine the capacity of the service panel
20: Clearance volume
affects compressor capacity
has no effect on compressor capacity
varies depending on compressor speed
is the same on all compressors
21: Volts x amps equals
Watts
Inductance
Ohms Law
Impedance
22: On a day with low relative humidity, the two thermometers on a sling psychrometer will read
far apart or greater difference
a ling psychrometer doesn't have two theremometers.
nearly the same
2F difference
23: Instead of using a compressor, an absorption air-conditioning chiller uses which of the following as its driving force?
Oil
Electricity
Air
Heat
24: By using nitrogen within a pipe during brazing operation,