Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: What device measures the specific gravity of a substance?
Manometer
Hydrometer
Thermometer
Hygrometer
2: An evaporator coil located near heating coil shall have a pressure-relief device installed within ______ inches of the evaporator.
24
48
36
18
3: A 24 volt transformer with a 240 volt primary can handle how many amps?
10 amps
There isn't enough information to answer.
20 amps
24 amps
4: Name a CFC refrigerant(s):
R-11
R-12
R-123
both a & b
5: What is the minimum height refrigeration piping should be placed against walls?
Ceiling height
7.25'
6'
72"
6: 1 Watt = ______ BTU's?
7.216
3.412
12
4.482
7: What type of pressure relief device is used on a CO2 system?
Rupture disk
Glove valve
Fusible plug
Gate valve
8: A 50 VA control transformer with a 25 volt control output would be rated for _________ amps.
2.5
1250
2
There isn't enough information to answer.
9: Booster compressors connect to the ____ side of the compressor
vapor
liquid
low side
oil side
10: 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.
80
110
90
100
11: Mercury was used in thermometers primarily because it
never freezes
vaporizes at very high temperatures
was inexpensive
expands uniformly
12: What should never be used in pressure testing refrigeration systems?
Oxygen
Compressed air
Nitrogen
Both a and b
13: A declaration test is needed when the system contains more than
55 lbs
65 lbs
120 lbs
110 lbs
14: If the suction pressure is low and the evaporator temperature high, the cause will be a?
overcharged
starved evaporator
too small evaporator
compressor suction valve stuck open
15: The critical temperature of a refrigerant gas occurs when
the gas is no longer saturated
any decrease in pressure will cause condensation
the gas returns to a liquid
any increase in pressure will not liquefy the gas
16: A premise or that portion of a premise where large numbers of people congregate and from which occupants cannot quickly vacate the space such as auditoriums, ballrooms, classrooms, passenger depots, restaurants, and theaters is considered a(n)
public assembly occupancy
commercial occupancy
illegal occupancy
institutional occupancy
17: A chiller entering and leaving temperature difference is?
10 degrees F
50 degrees F
5 degrees F
20 degrees F
18: Low pressure systems have what kind of compressor?
Rotary
Reciprocating
Scroll
Centrifugal
19: What is the typical air conditioning operating pressures for R-22?
60 psi suction 210 psi discharge
25 psi suction 125 psi discharge
105 psi suction 340 psi discharge
None of the above
20: Brazed joints melt at temperatures above
1,200F
500F
1,000F
800F
21: In a low temperature refrigeration system, the benefit of the system using P.A.G. oil is
it is hydroscopic
it traps moisture
viscosity
all of the above
22: Excessive head pressure is often caused by
air cooled condenser is plugged
leaking reed valve on the discharge side
insufficient refrigerant
thermostat set too high
23: A multi-evaporator refrigeration system uses what type of valve to maintain evaporating temperatures?
EEV
CPR valve
Solenoid valve
EPR valve
24: What must be done to refrigerant pipes before being buried?
Certified
Leaked checked
Coated
Encased
25: A line voltage thermostat controls a 1,200 watt strip header at 120 volts. What must be minimum ampere rated of the stat be?