Massachusetts Refrigeration Tech/Contractors practice quiz
Refrigeration RT/RC Prep Quiz
Topics: All categories in the pool
1: Ammonia systems use ____ pressure to adjust oil pressure
discharge
liquid
stream
air
2: A chilled water pump suction gauge reads 10 psig. Discharge gauge reads 48 psig. The head in feet of the pump is working against
116
38
88
108
3: 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
4: 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.
2F difference
nearly the same
5: Crankcase heaters are energized
when the compressor is off
to prevent compressor freeze-up
while the compressor is running
to allow easy compressor start-up
6: A total of all group A-2,B-2, A-3, and B-3 refrigerants shall not exceed ____ lb in the occupied areas and machinery rooms of institutional occupancies.
550
50
100
350
7: If the dry bulb temperature is 85F and the wet bulb temperature is 70F, the dew point temperature will be approximately (use psychometric chart)
32F
58F
70F
77F
8: Relief valves are rated in
gallons of water per hour
pounds of air per minute
gallons of water per minute
pounds of air per hour
9: Refrigeration devices shall be equipped with a ____ to protect against unexpected pressure due to a malfunction or fire?
T&P device
Circuit Breaker
Relief valve
Temperature limiter device
10: In a horizontal shell & tube condenser, the ammonia is liquefied by
removing the latent heat of vaporization
passing thru the tubes from top to bottom
water sprayed over condenser
removing the latent heat of fusion
11: Which refrigerant class listed below is the most flammable?
B-2
A-1
A-3
C-3
12: How many forces operate a thermostatic expansion valve?
1
4
3
2
13: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
specific heat
lost heat
sensible heat
latent heat
14: The principle used in continuous type absorption systems is
Charles's Law
Dalton's Law
Ohm's Law
Boyle's Law
15: How many groups of refrigerants are there?
7
3
5
1
16: What are the three components of a transformer?
Contacts, secondary coil, and core
Primary coil, secondary coil, and copper contacts
Primary core, secondary coil, and high and low voltage connectors.
Primary coil, secondary coil, and core
17: Name a CFC refrigerant(s):
R-11
R-12
R-123
both a & b
18: Aluminum, Zinc, Magnesium, or their alloys shall not be used in contact with
trichlorotrifluoromethane
ammonia
methyl chloride
R-718
19: A motor starter contains a thermal overload and a
solenoid
contactor
3-way relay
transformer
20: The boiling point of a refrigerant is based on
Temperature
Heat content
a pressure-temperature relationship
None of the above.
21: What is used to check very low pressure?
Velometer
Hygrometer
Hydrometer
Manometer
22: The purpose of a receiver is
a vessel to store refrigerant outside the system
to increase the capacity that the system can hold
to use a a later date
all of the above
23: Low pressure chiller systems use what type of compressor?
Reciprocating
Centrifugal
Screw
Scroll
24: The formula for Pure Power in a resistance circuit is
Watts X amps.
Watts = volts X amps
Watts X power factor
Kw = volts X amps
25: What effect does the temperature of air have on humidity?