Multiple Choice Identify the
choice that best completes the statement or answers the question.
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1.
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What happens when room temperature soda is poured into a glass of ice?
a. | The ice gets colder. | b. | The ice melts because it is giving up the
"cold" to the soda. | c. | The ice melts because it is absorbing heat from
the soda. | d. | The ice melts because the soda is colder than the
ice. |
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2.
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Ice melts in iceboxes because ____.
a. | Heat flows through the insulated walls. | b. | Heat enters when the
door is opened | c. | Heat enters when warm food is placed in the icebox. | d. | All of the
above |
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3.
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High temperature refrigeration is that produced by ____.
a. | heat from a furnace | b. | an air-conditioning system | c. | the vegetable
cooling system of a refrigerator | d. | the freezer section of a
refrigerator |
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4.
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Refrigeration can be described as ____.
a. | the process of making products cold | b. | the process of introducing heat to a location
where it is not wanted | c. | the process of removing heat from a place where
it is not wanted to a place where it makes little or no difference | d. | none of the
above |
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5.
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The temperature inside the refrigerator fresh food section should be about
____.
a. | 25 degrees F | b. | 30 degrees F | c. | 35 degrees F
| d. | 40 degrees F |
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6.
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A ton of refrigeration is equal to ____.
a. | 1 ton of ice | b. | 288,000 Btu/24-hr. | c. | 144
Btu/hr. | d. | 12,000 Btu/min. |
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7.
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The ____ relationship correlates the vapor pressure and the boiling point of
water and is the basis for controlling the cooling system’s temperatures.
a. | boiling/pressure | b. | temperature/pressure | c. | temperature/vapor | d. | boiling/vapor |
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8.
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The ____ are used to change the vapor to a liquid and the liquid form back into
a vapor the refrigeration cycle.
a. | condenser and compressor | b. | compressor and expansion
device | c. | expansion device and evaporator | d. | condenser and
evaporator |
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9.
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The evaporator in a refrigeration system ____.
a. | reduces the boiling point of the refrigerant | b. | condenses the
refrigerant | c. | absorbs heat from the product to be cooled | d. | compresses the
refrigerant vapor |
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10.
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Reciprocating compressors have ____.
a. | a piston and cylinder | b. | two scrolls that mesh
together | c. | a rotor to compress the refrigerant | d. | a large fan compressor
component |
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11.
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The condenser ____.
a. | rejects the heat from the refrigerant | b. | controls the refrigerant flow throughout the
system | c. | adds superheat to the refrigerant | d. | all of the
above |
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12.
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When a refrigerant enters the compressor, it is a ____ and when it leaves the
compressor, it is a ____.
a. | low pressure low temperature superheated vapor, high pressure high temperature
superheated vapor | b. | low pressure low temperature superheated vapor,
low pressure low temperature subcooled vapor | c. | high pressure superheated vapor, low pressure
superheated vapor | d. | low pressure low temperature subcooled liquid,
high pressure high temperature superheated vapor |
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13.
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The compressor in a refrigeration system ____.
a. | raises the boiling point of the refrigerant | b. | pumps the
refrigerant throughout the system | c. | both a and b | d. | none of the
above |
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14.
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Good ventilation is important when working around refrigeration equipment
because modern refrigerants ____.
a. | are toxic and can poison you | b. | have an unpleasant odor | c. | are heavier than air
and may displace the oxygen around you | d. | both a and c |
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15.
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Which of the following refrigerants has the lowest boiling temperatures at
atmospheric pressure?
a. | R-12 | b. | R-22 | c. | R-134a | d. | R-502 |
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16.
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The law requires technicians to recover refrigerant from all refrigeration
systems so that they ____.
a. | will not be released into the atmosphere | b. | may be used
again | c. | may be reclaimed for future use | d. | all of the
above |
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True/False Indicate whether the
statement is true or false.
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1.
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Modern refrigerators have become state-of-the-art appliances and some models
even include automatic beverage and ice dispensers, built in television screens and connections to
the World Wide Web.
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2.
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The evaporator in a refrigeration system must be colder than the refrigerated
space in order to absorb heat.
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3.
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The boiling point of a refrigerant should be low enough at atmospheric pressure
to keep the system pressure above 0 psig when operating at low temperatures.
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4.
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If a cylinder of R-22 is moved from a 100°F truck body into an 80°F
shop, the quantity of liquid refrigerant in the cylinder will remain the same.
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5.
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The evaporator can be thought of as a “heat sponge.”
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6.
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Vapor is more dense than liquid and, as the liquid refrigerant boils, it has a
tendency to sink.
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7.
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The only location where the refrigerant vapor is superheated is in the
evaporator.
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8.
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Only liquid refrigerant should enter the metering device.
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9.
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The discharge gas from the compressor is a high pressure, high temperature,
superheated vapor.
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10.
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The halide leak detector should be used in well ventilated areas as the
resulting blue or green flame indicates that phosgene gas is being produced.
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11.
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An expansion valve is the pressure reducing device that controls the flow of
liquid refrigerant into the evaporator.
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Completion Complete each
statement.
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1.
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The four (4) major components of a vapor compression refrigeration system are
the compressor, condenser, evaporator, and ____________________.
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2.
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The refrigerant vapor picks up additional heat as it flows from the evaporator
to the compressor. The heat is picked up from the ____________________.
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3.
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The _________________________________ is referred to as a kinetic displacement
compressor.
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4.
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The ____________________________ is another positive displacement compressor and
is used for larger air conditioning and refrigeration applications.
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5.
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From a performance standpoint, a substitute for R-12 is
____________________.
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6.
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The amount of heat a refrigerant contains with -40 degree F as the 0 heat
content reference point is called ____________________.
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Short Answer
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1.
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When the refrigerant leaves the metering device, it is not 100% liquid.
Why?
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2.
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What is the purpose of the metering device?
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Matching
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Using the pressure temperature chart below, match the refrigerant with its
correct pressure at 40°F.
| REFRIGERANT | | REFRIGERANT | | REFRIGERANT | | | | | | | TEMP | _____________________ | TEMP | ______________________ | TEMP | ________________________ | °F | 12 | 22 | 134a | 502 | °F | 12 | 22 | 134a | 502 | °F | 12 | 22 | 134a | 502 | | | | | | | | | | | | | | | | –60 | 19.0 | 12.0 | | 7.2 | 12 | 15.8 | 34.7 | 13.2 | 43.2 | 42 | 38.8 | 71.4 | 37.0 | 83.8 | –55 | 17.3 | 9.2 | | 3.8 | 13 | 16.4 | 35.7 | 13.8 | 44.3 | 43 | 39.8 | 73.0 | 38.0 | 85.4 | –50 | 15.4 | 6.2 | | 0.2 | 14 | 17.1 | 36.7 | 14.4 | 45.4 | 44 | 40.7 | 74.5 | 39.0 | 87.0 | –45 | 13.3 | 2.7 | | 1.9 | 15 | 17.7 | 37.7 | 15.1 | 46.5 | 45 | 41.7 | 76.0 | 40.1 | 88.7 | –40 | 11.0 | 0.5 | 14.7 | 4.1 | 16 | 18.4 | 38.7 | 15.7 | 47.7 | 46 | 42.6 | 77.6 | 41.1 | 90.4 | –35 | 8.4 | 2.6 | 12.4 | 6.5 | 17 | 19.0 | 39.8 | 16.4 | 48.8 | 47 | 43.6 | 79.2 | 42.2 | 92.1 | –30 | 5.5 | 4.9 | 9.7 | 9.2 | 18 | 19.7 | 40.8 | 17.1 | 50.0 | 48 | 44.6 | 80.8 | 43.3 | 93.9 | –25 | 2.3 | 7.4 | 6.8 | 12.1 | 19 | 20.4 | 41.9 | 17.7 | 51.2 | 49 | 45.7 | 82.4 | 44.4 | 95.6 | –20 | 0.6 | 10.1 | 3.6 | 15.3 | 20 | 21.0 | 43.0 | 18.4 | 52.4 | 50 | 46.7 | 84.0 | 45.5 | 97.4 | –18 | 1.3 | 11.3 | 2.2 | 16.7 | 21 | 21.7 | 44.1 | 19.2 | 53.7 | 55 | 52.0 | 92.6 | 51.3 | 106.6 | –16 | 2.0 | 12.5 | 0.7 | 18.1 | 22 | 22.4 | 45.3 | 19.9 | 54.9 | 60 | 57.7 | 101.6 | 57.3 | 116.4 | –14 | 2.8 | 13.8 | 0.3 | 19.5 | 23 | 23.2 | 46.4 | 20.6 | 56.2 | 65 | 63.8 | 111.2 | 64.1 | 126.7 | –12 | 3.6 | 15.1 | 1.2 | 21.0 | 24 | 23.9 | 47.6 | 21.4 | 57.5 | 70 | 70.2 | 121.4 | 71.2 | 137.6 | –10 | 4.5 | 16.5 | 2.0 | 22.6 | 25 | 24.6 | 48.8 | 22.0 | 58.8 | 75 | 77.0 | 132.2 | 78.7 | 149.1 | –8 | 5.4 | 17.9 | 2.8 | 24.2 | 26 | 25.4 | 49.9 | 22.9 | 60.1 | 80 | 84.2 | 143.6 | 86.8 | 161.2 | –6 | 6.3 | 19.3 | 3.7 | 25.8 | 27 | 26.1 | 51.2 | 23.7 | 61.5 | 85 | 91.8 | 155.7 | 95.3 | 174.0 | –4 | 7.2 | 20.8 | 4.6 | 27.5 | 28 | 26.9 | 52.4 | 24.5 | 62.8 | 90 | 99.8 | 168.4 | 104.4 | 187.4 | –2 | 8.2 | 22.4 | 5.5 | 29.3 | 29 | 27.7 | 53.6 | 25.3 | 64.2 | 95 | 108.2 | 181.8 | 114.0 | 201.4 | 0 | 9.2 | 24.0 | 6.5 | 31.1 | 30 | 28.4 | 54.9 | 26.1 | 65.6 | 100 | 117.2 | 195.9 | 124.2 | 216.2 | 1 | 9.7 | 24.8 | 7.0 | 32.0 | 31 | 29.2 | 56.2 | 26.9 | 67.0 | 105 | 126.6 | 210.8 | 135.0 | 231.7 | 2 | 10.2 | 25.6 | 7.5 | 32.9 | 32 | 30.1 | 57.5 | 27.8 | 68.4 | 110 | 136.4 | 226.4 | 146.4 | 247.9 | 3 | 10.7 | 26.4 | 8.0 | 33.9 | 33 | 30.9 | 58.8 | 28.7 | 69.9 | 115 | 146.8 | 242.7 | 158.5 | 264.9 | 4 | 11.2 | 27.3 | 8.6 | 34.9 | 34 | 31.7 | 60.1 | 29.5 | 71.3 | 120 | 157.6 | 259.9 | 171.2 | 282.7 | 5 | 11.8 | 28.2 | 9.1 | 35.8 | 35 | 32.6 | 61.5 | 30.4 | 72.8 | 125 | 169.1 | 277.9 | 184.6 | 301.4 | 6 | 12.3 | 29.1 | 9.7 | 36.8 | 36 | 33.4 | 62.8 | 31.3 | 74.3 | 130 | 181.0 | 296.8 | 198.7 | 320.8 | 7 | 12.9 | 30.0 | 10.2 | 37.9 | 37 | 34.3 | 64.2 | 32.2 | 75.8 | 135 | 193.5 | 316.6 | 213.5 | 341.2 | 8 | 13.5 | 30.9 | 10.8 | 38.9 | 38 | 35.2 | 65.6 | 33.2 | 77.4 | 140 | 206.6 | 337.2 | 229.1 | 362.6 | 9 | 14.0 | 31.8 | 11.4 | 39.9 | 39 | 36.1 | 67.1 | 34.1 | 79.0 | 145 | 220.3 | 358.9 | 245.5 | 385.0 | 10 | 14.6 | 32.8 | 11.9 | 41.0 | 40 | 37.0 | 68.5 | 35.1 | 80.5 | 150 | 234.6 | 381.5 | 262.7 | 408.4 | 11 | 15.2 | 33.7 | 12.5 | 42.1 | 41 | 37.9 | 70.0 | 36.0 | 82.1 | 155 | 249.5 | 405.1 | 280.7 | 432.9 | | | | | | | | | | | | | | | | | | | | | | | | |
a. | R-12 | c. | R-502 | b. | R-134a | d. | R-22 |
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1.
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80.5 psig
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2.
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37 psig
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3.
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68.5 psig
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4.
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35.1 psig
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Match the refrigerant cylinder with the correct color code. a. | R-11 | f. | R-114 | b. | R-12 | g. | R-500 | c. | R-22 | h. | R-502 | d. | R-113 | i. | R-717 | e. | R-134a |
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5.
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orchid
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6.
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light blue
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7.
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green
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8.
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silver
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9.
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purple
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10.
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yellow orange
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11.
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white
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12.
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dark blue
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13.
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orange
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In the illustration below, identify the indicated components.
a. | Compressor | c. | Metering Device | b. | Evaporator | d. | Condenser |
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14.
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abort heat from the system
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15.
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is the heart of the refrigeration system
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16.
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rejects both sensible and latent heat from the refrigeration system
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17.
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a valve or small fixed-size tubing or orifice that meters liquid refrigerant
into the evaporator
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