WorksheetsHVAC State Test Prep 12
Total questions: 49
Worksheet time: 40mins
Name
Class
Date
1.
Freon-11 has a boiling point of:
a)
-100 degrees F
b)
32 degrees F
c)
212 degrees F
d)
74.8 degrees F
2.
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
3.
What type of compressors make good use of R-12?
a)
reciprocating compressors
b)
rotary compressors
c)
screw compressors
d)
desiccant compressors
4.
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
5.
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
6.
With what type of compressor does Freon-21 refrigerate work best?
a)
reciprocating
b)
rotary vane
c)
piston
d)
absorption
7.
Freon-22 has a boiling point of _________ degrees F.
a)
48
b)
212
c)
32
d)
-41.4
8.
What type of compressor works best with R-22?
a)
rotary-vane type
b)
reciprocating
c)
absorption system
d)
screw type
9.
Where is R-22 used today?
a)
in azeotropic compressors
b)
in piston compressors
c)
in rotary-vane compressors
d)
in home air-conditioners
10.
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
11.
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
12.
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
13.
What type of compressor does the R-114 work with efficiently?
a)
adsorption
b)
absorption
c)
compression
d)
rotary vane
14.
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
15.
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
16.
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
17.
Freon refrigerants are colorless and almost _________.
a)
odorless
b)
impure
c)
tasteless
d)
flammable
18.
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
19.
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
20.
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
21.
Freon is nonflammable and _________ under conditions where appreciable quantities contact flame or hot metal surfaces.
a)
noncompressible
b)
nonpoisonous
c)
noncombustible
d)
noncolorable
22.
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
23.
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
24.
Volumes of liquid required to circulate for a given refrigerant effect should be _________.
a)
reduced
b)
elevated
c)
low
d)
high
25.
One of the requirements of an ideal refrigerant is that it must be _________.
a)
toxic
b)
nontoxic
c)
easily vaporized
d)
easily compressed
26.
What is another name for Freon R-12?
a)
sulfur dioxide
b)
carbon dioxide
c)
ammonia
d)
Carrene
27.
Freon-12 has a relatively _________ volume displacement.
a)
high
b)
low
c)
medium
d)
extreme
28.
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
29.
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
30.
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
31.
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
32.
The evaporator pressure is the _________ side in the system.
a)
high
b)
low
c)
very high
d)
very low
33.
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
34.
Except for carbon dioxide and ethane, all common refrigerants have satisfactorily high _________ temperatures.
a)
evaporator
b)
condenser
c)
critical
d)
compressor
35.
Dupont’s brand name for its widely used refrigerant R-134a is __________.
a)
CFC-12
b)
HFC-1
c)
Autosmart
d)
Suva
36.
Refrigerants with high Btu refrigerating effects are not always __________.
a)
available
b)
free of contamination
c)
desirable
d)
used
37.
A low specific heat of the liquid is _________ in a refrigerant.
a)
unwanted
b)
preferred
c)
desirable
d)
undesirable
38.
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
39.
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
40.
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
41.
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
42.
Refrigerant cylinders should be stored in a dry, sheltered, and _________ area.
a)
well-ventilated
b)
enclosed
c)
open
d)
none of the above
43.
Refrigerant cylinders should not be exposed to continuous dampness, salt water, or salt __________.
a)
nuggets
b)
spray
c)
crystals
d)
air
44.
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
45.
Lubricity refers to the lubricant’s ability to protect the metal surfaces from __________.
a)
abrasion
b)
wear
c)
disintegrating
d)
contamination
46.
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
47.
Automotive AC systems may use polyalkaline glycols, which are abbreviated as:
a)
HFCs
b)
alkalines
c)
PAGs
d)
POEs
48.
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
49.
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
100 %
