WorksheetsHVAC Unlimited Test Prep 2 of 2
Total questions: 225
Worksheet time: 8hrs 30mins
Name
Class
Date
1.
Enthalpy is the total amount of _________ contained in the air above 0 degrees F.
a)
ice
b)
heat
c)
fog
d)
humidity
2.
The centigrade scale is now referred to as Celsius.
a)
T
b)
F
3.
Absolute temperatures are measured from absolute zero.
a)
T
b)
F
4.
At a constant temperature, as the absolute temperature of a perfect gas varies, its absolute pressure will vary indirectly.
a)
T
b)
F
5.
Psychrometry is the science and practice of air mixtures and their control.
a)
T
b)
F
6.
Absolute zero is the point at which there is no heat.
a)
T
b)
F
7.
A barometer is used to measure the compressor’s pressure.
a)
T
b)
F
8.
All devices that measure pressure must be exposed to two pressures. The measurement is always the difference between two pressures, such as gauge pressure and atmospheric pressure
a)
T
b)
F
9.
Pressures that include atmospheric pressure are designated pounds per square inch absolute or psia.
a)
T
b)
F
10.
A mercury manometer is an accurate instrument for measuring pressure.
a)
T
b)
F
11.
When used for low pressure measurements, such as in an air-distribution duct, the manometer can use water instead of mercury in the U-tube.
a)
T
b)
F
12.
The Bourdon (spring) tube gauge is as sensitive and accurate as the manometer or barometer.
a)
T
b)
F
13.
A hygrometer is an instrument used to measure the amount of moisture in the air.
a)
T
b)
F
14.
Seven thousand grains of water equal 1 pound.
a)
T
b)
F
15.
The amount of water vapor that air can hold is determined by the temperature.
a)
T
b)
F
16.
Dew-point temperature is the temperature below which moisture will condense out of air.
a)
T
b)
F
17.
In reference to relative humidity, 100 percent saturation means the wet-bulb temperatures are the same as the dry-bulb and dew-point temperatures.
a)
T
b)
F
18.
Why is Freon being replaced as a refrigerate?
a)
it is poisonous
b)
it is too expensive
c)
it is damaging the environment
d)
it is not suited for safe operation in confined places
19.
Freon-11 has a boiling point of:
a)
-100 degrees F
b)
32 degrees F
c)
212 degrees F
d)
74.8 degrees F
20.
Where is R-12 most often used as a refrigerate?
a)
household and commercial refrigeration
b)
automobile air conditioners
c)
processing equipment
d)
none of these
21.
What type of compressors make good use of R-12?
a)
reciprocating compressors
b)
rotary compressors
c)
screw compressors
d)
desiccant compressors
22.
What is the boiling point of Freon-13?
a)
100 degrees F
b)
-144.6 degrees F
c)
74.8 degrees F
d)
32 degrees F
23.
What is the boiling point of Freon-21?
a)
74.8 degrees F
b)
100 degrees F
c)
48 degrees F
d)
32 degrees F
24.
With what type of compressor does Freon-21 refrigerate work best?
a)
reciprocating
b)
rotary vane
c)
piston
d)
absorption
25.
Freon-22 has a boiling point of _________ degrees F.
a)
48
b)
212
c)
32
d)
-41.4
26.
What type of compressor works best with R-22?
a)
rotary-vane type
b)
reciprocating
c)
absorption system
d)
screw type
27.
Where is R-22 used today?
a)
in azeotropic compressors
b)
in piston compressors
c)
in rotary-vane compressors
d)
in home air-conditioners
28.
The boiling point of Freon 113 is:
a)
48 degrees F
b)
−41.4 degrees F
c)
100 degrees F
d)
117.6 degrees F
29.
Where is R-113 most frequently used?
a)
in small tonnage applications
b)
in large tonnage applications
c)
in outdoor compressors
d)
in indoor compressors
30.
The boiling point of R-114 is:
a)
32.0 degrees F
b)
48.2 degrees F
c)
38.4 degrees F
d)
200 degrees F
31.
What type of compressor does the R-114 work with efficiently?
a)
adsorption
b)
absorption
c)
compression
d)
rotary vane
32.
What is the boiling point for R-115?
a)
32.8 degrees F
b)
38.4 degrees F
c)
–41.4 degrees F
d)
–37.7 degrees F
33.
Where is R-115 most frequently used?
a)
in high-discharge temperatures in reciprocating compressors
b)
in household refrigerators and automobile AC
c)
in commercial freezers
d)
in industrial applications
34.
Freon-502 is a(n) _________ mixture composed of 48.8 percent Freon-22 and 51.2 percent Freon-
a)
azeotropic
b)
asbestos-based
c)
ready-mixed
d)
latex-based
35.
Freon refrigerants are colorless and almost _________.
a)
odorless
b)
impure
c)
tasteless
d)
flammable
36.
Chemically, Freon refrigerants are inert, _________, and stable up to temperatures far beyond conditions found in actual operation.
a)
colorless
b)
odorless
c)
thermally
d)
dangerously
37.
How is Freon harmful if released into the atmosphere?
a)
it depletes the ozone layer around the earth
b)
it is highly toxic to vegetation
c)
it is highly toxic to people
d)
it is harmful to wildlife
38.
What are the determining factors involved with compressor displacement?
a)
compressor type
b)
compression ratio
c)
refrigerating effect and specific volume of the refrigerant vapor
d)
amount of ultraviolet rays radiated
39.
Freon is nonflammable and _________ under conditions where appreciable quantities contact flame or hot metal surfaces.
a)
noncompressible
b)
nonpoisonous
c)
noncombustible
d)
noncolorable
40.
How many pounds of R-114 refrigerant must be expanded per minute to produce refrigeration? See Table 12.1.
a)
4.64
b)
2.237
c)
2.887
d)
3.916
41.
The amount of work required to produce a given refrigerating effect increases as the temperature level to which the heat is pumped from the cold body is _________.
a)
lowered
b)
increased
c)
decreased
d)
none of these
42.
Volumes of liquid required to circulate for a given refrigerant effect should be _________.
a)
reduced
b)
elevated
c)
low
d)
high
43.
One of the requirements of an ideal refrigerant is that it must be _________.
a)
toxic
b)
nontoxic
c)
easily vaporized
d)
easily compressed
44.
What is another name for Freon R-12?
a)
sulfur dioxide
b)
carbon dioxide
c)
ammonia
d)
Carrene
45.
Freon-12 has a relatively _________ volume displacement.
a)
high
b)
low
c)
medium
d)
extreme
46.
In dealing with condensers, it is the _________ condensing pressure that must be kept in mind for leakage and other problems.
a)
high
b)
low
c)
extreme
d)
miniscule
47.
The freezing point of a refrigerant should be _________ any temperature that might be encountered in the system.
a)
near
b)
above
c)
below
d)
around
48.
High condensing pressure has a tendency to _________ leakage on the low side as well as on the high side when pressure builds up during idle periods.
a)
reduce
b)
decrease
c)
increase
d)
not allow
49.
The freezing point of a refrigerant should be _________ any temperature that might be encountered in the system.
a)
around
b)
near
c)
above
d)
below
50.
The evaporator pressure is the _________ side in the system.
a)
high
b)
low
c)
very high
d)
very low
51.
The critical temperature of a refrigerant is the _________ temperature at which it can be condensed to a liquid, regardless of a higher pressure.
a)
highest
b)
lowest
c)
best
d)
nominal
52.
Except for carbon dioxide and ethane, all common refrigerants have satisfactorily high _________ temperatures.
a)
evaporator
b)
condenser
c)
critical
d)
compressor
53.
Dupont’s brand name for its widely used refrigerant R-134a is __________.
a)
CFC-12
b)
HFC-1
c)
Autosmart
d)
Suva
54.
Refrigerants with high Btu refrigerating effects are not always __________.
a)
available
b)
free of contamination
c)
desirable
d)
used
55.
A low specific heat of the liquid is _________ in a refrigerant.
a)
unwanted
b)
preferred
c)
desirable
d)
undesirable
56.
In a perfect system, _________ Btu is the maximum refrigeration obtainable per Btu of energy used to operate the refrigeration system.
a)
5.74
b)
6
c)
7.33
d)
9.01
57.
The amount of work required to produce a given refrigerating effect increases as the temperature level to which the heat is pumped from the cold body is __________.
a)
increased
b)
decreased
c)
moderated
d)
slowly changed
58.
Which two of the older refrigerants can cause suffocation when in vapor form?
a)
sulfur dioxide and ammonia
b)
carbon dioxide and ammonia
c)
sulfur dioxide and carbon dioxide
d)
none of these
59.
Remember that liquid refrigerant will refrigerate or remove heat from anything it meets when released from a container. In the case of contact with refrigerant, the affected area should be treated as if it has been _________ or frostbitten.
a)
frozen
b)
scraped
c)
scarred
d)
burned
60.
Refrigerant cylinders should be stored in a dry, sheltered, and _________ area.
a)
well-ventilated
b)
enclosed
c)
open
d)
none of the above
61.
Refrigerant cylinders should not be exposed to continuous dampness, salt water, or salt __________.
a)
nuggets
b)
spray
c)
crystals
d)
air
62.
There are three basic properties that lubricants must possess. Which of the following is not one of them?
a)
viscosity
b)
chemical stability
c)
lubricity
d)
liquidity
63.
Lubricity refers to the lubricant’s ability to protect the metal surfaces from __________.
a)
abrasion
b)
wear
c)
disintegrating
d)
contamination
64.
The blended refrigerant R-134a is a long-term, HFC alternative with similar properties to __________.
a)
R-114
b)
R-501
c)
R-12
d)
R-22
65.
Automotive AC systems may use polyalkaline glycols, which are abbreviated as:
a)
HFCs
b)
alkalines
c)
PAGs
d)
POEs
66.
Retrofitting equipment with a substitute for R-12 is sometimes _________ because there are a number of considerations to be examined before undertaking the task.
a)
difficult
b)
easy
c)
demanding
d)
expensive
67.
Another blended refrigerant that can be used to substitute for R-12 is __________.
a)
R-22
b)
R-401A
c)
R-401B
d)
R-402B
68.
The EPA listing of reclaimers is updated when additional refrigerant reclaimers are approved.
a)
T
b)
F
69.
An EPA reclaimer program is voluntary and the certification program is operated by the ARI.
a)
T
b)
F
70.
Freon-11 is also employed as brine for low-temperature applications.
a)
T
b)
F
71.
Freon R-12 is the most widely used refrigerant.
a)
T
b)
F
72.
The automotive industry has replaced R-12 in car air conditioners with R-134a.
a)
T
b)
F
73.
In 1987, the Montreal Protocol established requirements that began the worldwide phase out of ozone-depleting CFCs.
a)
T
b)
F
74.
The Clean Air Act does not allow any refrigerant to be vented into the atmosphere during installation.
a)
T
b)
F
75.
After 2020, the servicing of R-22-based systems will rely on recycled refrigerants.
a)
T
b)
F
76.
Existing units using R-22 can continue to be serviced with R-22.
a)
T
b)
F
77.
One of the substitutes for R-22 is R-410A.
a)
T
b)
F
78.
The Clean Air Act outlines specific refrigerant containment and management practices for HVAC manufacturers, distributors, dealers, and technicians.
a)
T
b)
F
79.
The handling and recycling of refrigerants used in motor vehicle air-conditioning systems are governed under section 609 of the Clean Air Act.
a)
T
b)
F
80.
If a leak is discovered in commercial equipment, owners or operators have 30 days to obtain a repair.
a)
T
b)
F
81.
The technician who repairs or recharges equipment must be EPA- or ARI-certified as a reclaimer.
a)
T
b)
F
82.
It is still legal under certain circumstances to vent refrigerant into the atmosphere.
a)
T
b)
F
83.
It is easy to replace R-12 with newer refrigerants.
a)
T
b)
F
84.
Hot air furnaces are self-contained and self- __________ units.
a)
healing
b)
enclosed
c)
cleaning
d)
stoking
85.
Why does hot air rise?
a)
when heated it becomes lighter
b)
when heated it gains oxygen and floats
c)
when heated it becomes heavier
d)
when heated it sinks slowly
86.
After the hot air loses its heat, it becomes cooler and __________.
a)
heavier
b)
lighter
c)
moisture laden
d)
freezes
87.
What is the most popular furnace used to heat houses in this country?
a)
propane gas
b)
natural-gas
c)
butane gas
d)
coal gas
88.
What controls the operation of the gas solenoid?
a)
igniter switch
b)
printed circuit switch
c)
blower switch
d)
thermostat
89.
How hot does the air in the plenum have to be before the fan switch closes and the fan starts?
a)
95 degrees F
b)
100 degrees F
c)
120 degrees F
d)
125 degrees F
90.
What is the voltage required for the fan motor to operate?
a)
240
b)
120
c)
12
d)
24
91.
How low does the temperature in the plenum have to drop to cause the fan to stop?
a)
100 degrees F
b)
90 degrees F
c)
85 degrees F
d)
75 degrees F
92.
Why do electric-fired furnaces need large amounts of current to operate?
a)
the heating elements draw high current
b)
the fans draw a lot of current
c)
the heat exchanger is very inefficient
d)
none of the above
93.
How fast does the electric-fired furnace begin producing heat?
a)
5 minutes
b)
instantly
c)
slowly
d)
none of the above
94.
Why aren’t all the heating elements turned on at the same time?
a)
to prevent an overload on the electrical circuits in the house
b)
to prevent a switching problem
c)
to prevent excess heat being generated
d)
to prevent fuse blowing
95.
What voltage does the heating elements in an electric-fired furnace use?
a)
240
b)
120
c)
440
d)
880
96.
Why are ladder diagrams easy to read?
a)
they are often used for printed circuit boards
b)
they have everything labeled
c)
they make it easy to wire the circuits in production
d)
they look like a ladder and devices and switches are connected like rungs in a ladder
97.
What does EFR stand for on a ladder diagram?
a)
evaporator function relay
b)
evaporator fail-safe relay
c)
evaporator fan relay
d)
none of the above
98.
What does CC on a ladder diagram represent?
a)
compressor cleaner
b)
compressor control
c)
compressor contactor
d)
condenser control
99.
On furnace manufacturers’ diagrams, what do the dotted lines represent?
a)
high voltage lines
b)
control lines
c)
low voltage line to be furnished at installation
d)
power lines for fans and controls
100.
At what speed are fans’ electric motors set as they come from the factory?
a)
medium
b)
medium-high
c)
high
d)
low
101.
In electrical wiring for air-conditioners or refrigerators, what does the white wire represent in the three
a)
ground or neutral
b)
hot side
c)
low voltage
102.
The gas valve is wired by having low voltage wires from the __________ connected so that one wire is attached to one side of the solenoid and the other from the limit-switch to the other side of the solenoid.
a)
transformer
b)
solenoid
c)
gas valve
103.
Where is the wiring diagram for a furnace located as it comes from the factory?
a)
inside the cover for the cold-air return
b)
in the plenum
c)
in the hot air ductwork
104.
All electrical connections should comply with the __________ electrical code.
a)
county
b)
local
c)
international
d)
national
105.
What happens when the heat anticipator is not adjusted and set to factory specs?
a)
improper use of the fans
b)
improper operation of the solenoid
c)
improper operation of the gas valve
d)
improper operation of the thermostat
106.
The room __________ should be located where it will be in the natural circulating path of room air.
a)
thermostat
b)
fan
c)
ventilator
107.
The series circuit has __________ amount of current in all parts of the circuit.
a)
the same
b)
a lesser
c)
a greater
108.
Why should the furnace cabinet have an un-interrupted or unbroken electrical ground?
a)
to minimize personal injury
b)
to maximize personal injury
c)
to protect the equipment from dust
d)
to protect the blower mechanism from damage
109.
Which of the following is not a desirable place to locate a thermostat?
a)
behind doors
b)
near a cold-air register
c)
near drafts from windows
d)
in the sunlight
e)
all of the above none of the above
110.
The heat pump is a heat __________.
a)
generator
b)
manipulator
c)
regular pump
d)
multiplier
111.
What does the heat pump do to air to heat it?
a)
it adds refrigeration to the air
b)
it decompresses the air
c)
it compresses the air
d)
it contaminates the air
112.
The heat pump can take the heat generated by a refrigeration unit and use it to __________ a house or room.
a)
decontaminate
b)
cool
c)
heat
d)
dehumidify
113.
How is the heat pump system augmented to produce heating in extremely cold weather?
a)
electrical heat is switched on and the heat pump is deactivated
b)
gas heat is switched on and the heat pump is also activated
c)
propane heat is substituted for the heat pump
d)
sunshine is relied upon for supplemental heat
114.
During the defrost cycle, the heat pump switches from heating to __________.
a)
idle
b)
cooling
c)
ventilating
d)
freezing
115.
In a straight heat pump/supplementary electric heater application, at least one outdoor __________ is required to cycle the heaters as the outdoor temperature drops.
a)
compressor
b)
transformer
c)
thermostat
d)
fan
116.
In a heat pump installation, the supply ducts must be properly sized and __________.
a)
insulated
b)
installed
c)
leaded
d)
sealed
117.
Newer furnaces have been designed with efficiencies up to __________ percent.
a)
55
b)
85
c)
80
d)
97
118.
High-efficiency furnaces achieve a higher level of fuel conversion by using a __________ heatexchanger design.
a)
unique
b)
different
c)
slower
d)
faster
119.
How are exhaust gases from the Pulse furnace conducted to the outside?
a)
by using a sheet-metal stack
b)
by using a PVC pipe
c)
by using a rubberized chimney
d)
by using lead pipe
120.
The Pulse furnace has no pilot light or __________.
a)
burners
b)
chimney problems
c)
open flame
d)
none of the above
121.
In the Pulse furnace, the pre-purge cycle lasts ________ seconds.
a)
33
b)
34
c)
35
d)
36
122.
In the Pulse furnace, the furnace blower operation is initiated in 30 to ____ seconds after combustion ignition.
a)
60
b)
35
c)
45
d)
50
123.
In the Pulse furnace, each pulse of gas/air mixture is ignited at the rate of 60 to __________ times per second.
a)
65
b)
70
c)
75
d)
80
124.
Hot air furnaces are self-contained and self-enclosed units.
a)
T
b)
F
125.
After hot air loses its heat, it becomes cooler and heavier.
a)
T
b)
F
126.
The gas furnace is the simplest to operate and understand.
a)
T
b)
F
127.
When the air in the plenum reaches 90 degrees F, the fan switch closes and the blower fan starts.
a)
T
b)
F
128.
A transformer is needed to provide low voltage for control circuits.
a)
T
b)
F
129.
The fan switch provides the necessary 120 volts to the fan motor for it to operate.
a)
T
b)
F
130.
Once the room has heated up to the desired thermostat setting, the thermostat closes.
a)
T
b)
F
131.
Electric-fired heat is the only heat produced almost as fast as the thermostat calls for it.
a)
T
b)
F
132.
The outside of an electric-fired furnace looks almost the same as a gas-fired furnace.
a)
T
b)
F
133.
After the gas has been turned off, the blower continues to operate until the temperature in the plenum hits a pre-set point.
a)
T
b)
F
134.
The low-resistance heating element used in an electric-fired furnace draws a lot of current.
a)
T
b)
F
135.
In the electric-fired furnace, when the auxiliary contacts open they remove the heating element from the line and stop the fan motor.
a)
T
b)
F
136.
The ladder diagram makes it easier to see how devices connected to the line are wired.
a)
T
b)
F
137.
The EFR evaporator fan relay also controls the blower fan.
a)
T
b)
F
138.
The evaporator fan will operate when either the heating relay or the evaporator fan relay is energized.
a)
T
b)
F
139.
The wiring diagram is usually located inside the cover for the cold air return when it comes from the factory.
a)
T
b)
F
140.
All electrical connections made in the field should be done in accordance with the American Electrical Code.
a)
T
b)
F
141.
The room thermostat should be located where it will be in the natural circulating path of room air.
a)
T
b)
F
142.
The thermostat should not be exposed to heat from nearby fireplaces, radios, televisions, lamps, or rays from the sun.
a)
T
b)
F
143.
Newer hot-air furnaces feature printed circuit controls.
a)
T
b)
F
144.
The heat pump is a heat multiplier.
a)
T
b)
F
145.
The heat pump can take the heat generated by a refrigeration unit and use it to heat a room or whole house.
a)
T
b)
F
146.
On mild temperature days, the heat pump handles all heating needs.
a)
T
b)
F
147.
When the second-stage furnace is satisfied and the plenum temperature has cooled to below 90 and 100 degrees F, the heat pump relay turns the heat pump on and controls the conditioned space until the second-stage operation is required again.
a)
T
b)
F
148.
During the defrost cycle, the heat pump switches from heating to cooling.
a)
T
b)
F
149.
If after a defrost cycle, the air downstream of the coil gets above 115 degrees F, the closing point of the heat-pump relay, the compressor will stop until the heat exchanger has cooled down to 90 to 100 degrees F as it does during normal cycling operation.
a)
T
b)
F
150.
During the summer cooling season, the heat pump works as a split system.
a)
T
b)
F
151.
The installation, maintenance, and operating efficiency of the heat-pump system are like those of all other comfort systems.
a)
T
b)
F
152.
In the heat-pump system. the air distribution system and diffuser locations are not too important.
a)
T
b)
F
153.
There are four ways to describe the heat-pump methods of transporting heat into the house.
a)
T
b)
F
154.
Newer furnaces have been designed with efficiencies of up to 97 percent.
a)
T
b)
F
155.
High-efficiency furnaces achieve a high level of fuel conversion by using a unique heat-exchanger design.
a)
T
b)
F
156.
The Pulse furnace uses a spark plug for an igniter.
a)
T
b)
F
157.
The Pulse furnace uses a pilot light.
a)
T
b)
F
158.
The Pulse furnace uses PVC for connections to the outside air.
a)
T
b)
F
159.
The gas furnace is the simplest to operate and understand.
a)
T
b)
F
160.
Which of the following is not considered a safety hazard?
a)
ignoring safety codes
b)
not wearing safety glasses
c)
not wearing steel-toed shoes
d)
having a fire extinguisher available
161.
Which of the following is not a recommended safety practice?
a)
following all safety codes
b)
wiring up the compressor with the power on
c)
reading instructions thoroughly and following them
d)
using a quenching cloth for brazing operations
162.
What is the symbol for safety alert?
a)
a triangle with an exclamation mark enclosed
b)
a circle with period enclosed
c)
a triangle with a flame in it
d)
a rectangle with the word “caution” written inside it
163.
Which of the following is not a signal word?
a)
danger
b)
warning
c)
help
d)
caution
164.
The word “danger” identifies the most serious hazards, which could result in personal injury or __________.
a)
harm
b)
amputation
c)
death
d)
hospitalization
165.
When working with electricity, it is important not to touch the __________ wire.
a)
low voltage
b)
gray
c)
green
d)
hot
166.
If you make contact with a white wire and a black wire, what voltage would you be aware of immediately?
a)
120
b)
240
c)
12
d)
24
167.
If you make contact with a white wire and a red wire, what voltage would you come across?
a)
120
b)
240
c)
12
d)
24
168.
If you are working on a piece of equipment and trying to wire it up and happen to get across the red and black wires in the power line, what would be the voltage present?
a)
120
b)
240
c)
12
d)
24
169.
While working with the thermostat circuit, you make contact with the two wires coming from the transformer secondary. What is the voltage you receive this time?
a)
200
b)
100
c)
12
d)
24
170.
The thermostat is in series with which component in a furnace circuit?
a)
transformer
b)
push button
c)
gas valve
d)
blower fan
171.
The following two wires in a 3-wire cable are ground wires:
a)
red and black wires
b)
red and white wires
c)
bare wire and white wire
d)
black and bare wire
172.
What type of capacitor is used as a start capacitor with a compressor motor?
a)
mica
b)
ceramic
c)
electrolytic
d)
paper
173.
What type of capacitor is used as a run capacitor with some motors?
a)
mica
b)
ceramic
c)
electrolytic
d)
silver plated
174.
With which motor is it recommended to not wear loose-fitting clothing?
a)
permanent-split capacitor
b)
split-phase capacitor
c)
start capacitor
d)
shaded pole capacitor
175.
How many times should you short across an electrolytic capacitor to prevent it from retaining a charge capable of doing physical harm?
a)
2
b)
4
c)
5
d)
6
176.
When working with heating equipment (hot-air furnace), it is very possible to get burned by the __________ exchanger.
a)
humidity
b)
cold
c)
heat
d)
root
177.
In working with cooling towers, what is the main safety hazard to be watchful for?
a)
chemicals
b)
scale
c)
water
d)
refrigerant
178.
In working with cooling towers, scale __________ contains acid and can cause skin irritation.
a)
residue
b)
coater
c)
reactor
d)
remover
179.
Do not drain the spent scale remover solution to the roof or to a(n) __________ tank.
a)
above ground
b)
septic
c)
disposal
d)
underground
180.
Wind drift can carry tiny droplets of ________ that can burn eyes and skin.
a)
salt water
b)
acid
c)
calcium chloride
d)
soap
181.
There are several uses for solvents and ________ in the ordinary maintenance schedule of cooling towers as well as of air-cooled tin-coil condensers, evaporator coils, permanent-type filters, and fan blades.
a)
detergents
b)
soaps
c)
steel wool
d)
sandpaper
182.
What method of cleaning is used in cleaning permanent-type filters?
a)
spraying
b)
dipping
c)
dripping
d)
hosing
183.
Cooling tower manufacturers design their units for:
a)
maximum efficiency no matter how they affect the environment
b)
minimum efficiency and maximum cooling
c)
a given performance standard
d)
fitting any location
184.
Refrigeration and air-conditioning mechanics must be able to handle __________ gases.
a)
hydrolyzed
b)
oxygenated
c)
compressed
d)
acetylenized
185.
Dry nitrogen or dry __________ dioxide are suitable gases for pressurizing refrigeration or airconditioning systems for leak tests.
a)
ferric
b)
carbon
c)
sodium
d)
calcium
186.
Which of the following gases should never be used to pressurize a refrigeration system?
a)
nitrogen
b)
acetylene
c)
hydrogen
d)
chlorine
187.
Commercial cylinders of carbon dioxide contain pressures in excess of __________ pounds/inch2 at normal room temperature.
a)
100
b)
200
c)
600
d)
800
188.
Never heat a gas-filled cylinder to a temperature over __________ degrees F.
a)
110
b)
220
c)
120
d)
230
189.
For leak testing and purging, a system can be pressurized up to a maximum of __________ psig.
a)
150
b)
200
c)
250
d)
300
190.
Fiberglass fans require care similar to steel fans.
a)
T
b)
F
191.
Do not operate a fiberglass fan in an abrasive atmosphere.
a)
T
b)
F
192.
Never attempt to support a fiberglass fan by one flange.
a)
T
b)
F
193.
Never allow a fiberglass fan to operate with a vibration problem.
a)
T
b)
F
194.
You can operate a fiberglass fan above 150 degrees F.
a)
T
b)
F
195.
Lifting heavy objects, like an evaporator coil, can cause serious problems.
a)
T
b)
F
196.
Before you attempt to service any refrigeration system, make sure that the main circuit breaker is open and all power is off.
a)
T
b)
F
197.
To avoid injury when lifting heavy objects, lift the safe way. Bend your knees.
a)
T
b)
F
198.
Improper installation, adjustment, alteration, service, maintenance, or use of refrigeration equipment can cause an explosion. Fire, electrical shock or other dangerous conditions may be encountered.
a)
T
b)
F
199.
Quenching clothes are necessary when brazing.
a)
T
b)
F
200.
One of the requirements of an ideal refrigerant is that it must be toxic.
a)
T
b)
F
201.
Refrigerants such as sulfur dioxide and ammonia can bring about serious illness.
a)
T
b)
F
202.
Vaporized refrigerants in enclosed areas can cause irritation and congestion of the lungs and bronchial organs.
a)
T
b)
F
203.
Carrene is another name for Freon R-12.
a)
T
b)
F
204.
A gas mask and goggles should be worn when working with ammonia as a refrigerant.
a)
T
b)
F
205.
When the human body has been exposed to a refrigerant with direct contact, the victim should treat the resulting area as if it were frozen or frostbitten.
a)
T
b)
F
206.
It is not necessary to store refrigerant cylinders in a dry, sheltered, and well-ventilated area.
a)
T
b)
F
207.
Never drop cylinders or permit them to strike each other violently.
a)
T
b)
F
208.
Never attempt to repair or alter valves.
a)
T
b)
F
209.
Never use a lifting magnet or a sling when handling cylinders.
a)
T
b)
F
210.
Caps are provided for valve protection on gas-filled cylinders.
a)
T
b)
F
211.
Never mix gases in a cylinder.
a)
T
b)
F
212.
Never overfill cylinders.
a)
T
b)
F
213.
Make sure that the threads on regulators or other unions are the same as those on the cylinder-valve outlets.
a)
T
b)
F
214.
Regulators and gauges provided for use with one gas can be used on cylinders containing a different gas.
a)
T
b)
F
215.
When storing cylinders, it is best to store them in a vertical position.
a)
T
b)
F
216.
A crane may be used to lift cylinders if a safe cradle is provided to hold the cylinders.
a)
T
b)
F
217.
Open the cylinder valves slowly.
a)
T
b)
F
218.
Never attempt to repair or alter cylinders.
a)
T
b)
F
219.
Store full and empty cylinders apart to avoid confusion.
a)
T
b)
F
220.
Never store cylinders near highly flammable substances such as oil, gasoline, or waste.
a)
T
b)
F
221.
Cylinders should not be exposed to continuous dampness, salt water, or salt spray.
a)
T
b)
F
222.
When working with refrigeration equipment, wear safety glasses and work gloves.
a)
T
b)
F
223.
When installing new refrigeration equipment, be sure to consult all local, state, and national codes for their requirements.
a)
T
b)
F
224.
Some compressors use a start-and-run capacitor for proper operation.
a)
T
b)
F
225.
When dispensing with spent solution from cooling tower cleaning, you can always drain the solution onto the roof or into the local septic tank.
a)
T
b)
F
100 %
