EPA Section 608: Core
EPA Section 608 Study Questions Pool
Section: CORE
Questions: 160
- 1.
Refrigeration technicians who violate the Clean Air Act can:
- A.
Lose their EPA certification
- B.
Be fined
- C.
Be required to appear in Federal court
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
Refrigeration technicians who violate the Clean Air Act can face multiple consequences. They can lose their EPA certification, which means they will no longer be authorized to work in the field. Additionally, they can be fined for their violation, which serves as a financial penalty. Lastly, they may be required to appear in Federal court to face legal consequences for their actions. Therefore, the correct answer is "all of the above" as all these consequences can apply to technicians who violate the Clean Air Act.Rate this question:
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- 2.
After 1995, any supplies of CFC refrigerant to service existing units in the USA can only come from:
- A.
Recovery and recycling
- B.
Solvent conversion
- C.
European chemical manufacturers
- D.
Third World chemical manufacturers
Correct Answer
A. Recovery and recyclingExplanation
After 1995, the supplies of CFC refrigerant to service existing units in the USA can only come from recovery and recycling. This is because the use of CFCs was phased out due to their harmful effects on the ozone layer. Recovery and recycling involve collecting and processing used CFC refrigerants to remove impurities and make them suitable for reuse. This approach helps to minimize the release of CFCs into the atmosphere and promotes the sustainable use of resources.Rate this question:
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- 3.
Refrigerant that is recovered can be returned to:
- A.
The same system or other systems owned by the same person without restriction
- B.
Used in any system serviced that day
- C.
Sold as used refrigerant to other customers
- D.
Called reclaimed if a filter-drier was used during recovery
Correct Answer
A. The same system or other systems owned by the same person without restrictionExplanation
Recovered refrigerant can be returned to the same system or other systems owned by the same person without any restrictions. This means that once the refrigerant has been recovered, it can be reused within the same system or in other systems owned by the same individual without any limitations or regulations. This allows for efficient and cost-effective use of the recovered refrigerant.Rate this question:
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- 4.
Refrigerant cannot be called "reclaimed" unless it:
- A.
Was processed in a reclaiming machine
- B.
Has been chemically analyzed and the refrigerant meets the ARI 700 purity standard.
- C.
Is recovered from a system less than 1 year old
- D.
Is recovered from a system still under warranty.
Correct Answer
B. Has been chemically analyzed and the refrigerant meets the ARI 700 purity standard.Explanation
To be called "reclaimed," refrigerant must undergo a chemical analysis to ensure that it meets the ARI 700 purity standard. This standard ensures that the refrigerant has been properly processed and purified, making it suitable for reuse. Simply being processed in a reclaiming machine or recovered from a system less than 1 year old or under warranty does not guarantee that the refrigerant has met the necessary purity requirements. Therefore, the correct answer is that the refrigerant must be chemically analyzed and meet the ARI 700 purity standard to be considered "reclaimed."Rate this question:
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- 5.
The EPA can require a technician to demonstrate their ability to perform proper procedures for recovering and /or recycling refrigerant. Failure to demonstrate competency can result in:
- A.
Revocation of the technician's certification
- B.
Seizure of the technician's recovery or recycling equipment.
- C.
Seizure of any refrigerant purchased by the technician which is still in his/her position.
- D.
Mandatory attendance at a refrigerant training camp
Correct Answer
A. Revocation of the technician's certificationExplanation
The EPA can require a technician to demonstrate their ability to perform proper procedures for recovering and/or recycling refrigerant. If the technician fails to demonstrate competency, their certification can be revoked. This means that they would no longer be recognized as a certified technician by the EPA.Rate this question:
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- 6.
What characteristic(s) of CFCs make them more likely to reach the stratosphere than most other compounds containing chlorine?
- A.
Refrigerants that contain chlorine but not hydrogen are so stable that they do not break down in the lower atmosphere after being released. The chlorine or bromine reacts with ozone causing it to change back to oxygen, thus destroying the ozone layer.
- B.
CFCs are lighter than other damaging compounds, making it easier for them to float upward when released.
- C.
CFCs are attracted to the static in the atmosphere
- D.
CFCs are attracted to dust in the atmosphere.
Correct Answer
A. Refrigerants that contain chlorine but not hydrogen are so stable that they do not break down in the lower atmosphere after being released. The chlorine or bromine reacts with ozone causing it to change back to oxygen, thus destroying the ozone layer.Explanation
CFCs are more likely to reach the stratosphere than most other compounds containing chlorine because they are stable and do not break down in the lower atmosphere after being released. The chlorine or bromine in CFCs reacts with ozone, causing it to change back to oxygen and leading to the destruction of the ozone layer.Rate this question:
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- 7.
A system is considered dehydrated when:
- A.
The vacuum indicator shows you have reached and held the required finished vacuum.
- B.
The vacuum pump has run at least 7 hours.
- C.
The manifold suction gauge has held a 30in hg./760 mm vacuum for 3 hours
- D.
You are ready to leave for the day
Correct Answer
A. The vacuum indicator shows you have reached and held the required finished vacuum. -
- 8.
Disposable refrigerant containers are used for ___ refrigerant.
- A.
Recycled
- B.
Recovered
- C.
Virgin
- D.
Both a and b
Correct Answer
C. VirginExplanation
Disposable refrigerant containers are used for virgin refrigerant. Virgin refrigerant refers to refrigerant that has not been used before and is in its original, pure form. These containers are specifically designed to hold and transport new refrigerant that has not been recycled or recovered from previous use. Using disposable containers ensures that the refrigerant is uncontaminated and meets the required specifications for use in refrigeration systems.Rate this question:
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- 9.
Which refrigerant is an HCFC?
- A.
R-124
- B.
R-134a
- C.
R-410a
- D.
R-12
Correct Answer
A. R-124Explanation
R-124 is the correct answer because it is a hydrochlorofluorocarbon (HCFC). HCFCs are a type of refrigerant that contain chlorine, fluorine, carbon, and hydrogen atoms. They were commonly used as refrigerants in the past but are being phased out due to their ozone depletion potential. R-134a is a hydrofluorocarbon (HFC), R-410a is a blend of HFCs, and R-12 is a chlorofluorocarbon (CFC), none of which are HCFCs.Rate this question:
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- 10.
What statement is true about an azeotropic refrigerant mixture?
- A.
It is always made from just two components
- B.
It has a pressure-temperature curve identical to one of its components.
- C.
It is a mixture that is always made from at least three component refrigerants
- D.
It is a mixture that acts like a single-component refrigerant over its entire range.
Correct Answer
D. It is a mixture that acts like a single-component refrigerant over its entire range.Explanation
An azeotropic refrigerant mixture is a blend of two or more refrigerants that behaves as a single-component refrigerant over its entire temperature range. This means that the mixture has a constant boiling point and vapor composition, regardless of the pressure or temperature. This property is desirable in refrigeration systems as it ensures consistent and predictable performance. Therefore, the statement "It is a mixture that acts like a single-component refrigerant over its entire range" accurately describes an azeotropic refrigerant mixture.Rate this question:
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- 11.
Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) have which of the following in common?
- A.
They have identical ODP's.
- B.
They both contain hydrogen.
- C.
They have the same normal boiling points.
- D.
They must be recovered before opening or disposing of applicances.
Correct Answer
D. They must be recovered before opening or disposing of applicances.Explanation
CFCs and HCFCs must be recovered before opening or disposing of appliances because they are both ozone-depleting substances. This means that when released into the atmosphere, they can break down ozone molecules in the ozone layer, leading to ozone depletion. Therefore, it is important to properly handle and dispose of appliances containing these substances to prevent their release into the atmosphere and minimize their harmful impact on the ozone layer.Rate this question:
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- 12.
To scrap a disposable cylinder, the internal cylinder pressure should be reduced to at least:
- A.
0 psig.
- B.
15 psig
- C.
20 psig
- D.
28.8 psig
Correct Answer
A. 0 psig.Explanation
To scrap a disposable cylinder, the internal cylinder pressure should be reduced to at least 0 psig. This is because a disposable cylinder is not designed to withstand high pressures and can be dangerous if not properly depressurized before disposal. Therefore, it is necessary to reduce the internal pressure to zero to ensure safe handling and disposal of the cylinder.Rate this question:
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- 13.
Manifold gauge sets are often color coded, when this is done, the high pressure gauge is color coded:
- A.
Red.
- B.
White
- C.
Blue
- D.
Yellow
Correct Answer
A. Red.Explanation
Manifold gauge sets are used to measure the pressure in various parts of a refrigeration system. The high pressure gauge, which measures the pressure on the high side of the system, is typically color coded for easy identification. In this case, the correct answer is red, indicating that the high pressure gauge is color coded in red. This color coding helps technicians quickly and accurately identify the correct gauge to use when working with the high pressure side of the system.Rate this question:
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- 14.
In general, blended refrigerants should be charged:
- A.
As a vapor
- B.
At very high temperatures
- C.
As a liquid.
- D.
The same as any other refrigerant
Correct Answer
C. As a liquid.Explanation
Blended refrigerants should be charged as a liquid because they are a mixture of different refrigerants with varying boiling points. Charging them as a liquid ensures that the correct ratio of the blend is maintained and prevents any separation or uneven distribution of the components. Charging as a vapor or at very high temperatures could result in improper blending and reduced efficiency of the refrigeration system. Therefore, charging blended refrigerants as a liquid is the recommended method.Rate this question:
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- 15.
Blended refrigerants leak from a system:
- A.
Faster than other refrigerants
- B.
In uneven amounts due to different vapor pressures.
- C.
Slower than other refrigerants
- D.
Only if the joint falls completely
Correct Answer
B. In uneven amounts due to different vapor pressures.Explanation
Blended refrigerants leak from a system in uneven amounts due to different vapor pressures. This means that different components of the blended refrigerants have different tendencies to vaporize and escape from the system. As a result, the leakage is not uniform and can vary depending on the specific composition of the blended refrigerants.Rate this question:
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- 16.
Which of the following gases help from the earth's protective shield?
- A.
Chlorine
- B.
Chlorides
- C.
Carbon Monoxide
- D.
Stratospheric Ozone.
Correct Answer
D. Stratospheric Ozone.Explanation
Stratospheric ozone is the correct answer because it forms a protective layer in the Earth's atmosphere. This layer absorbs most of the Sun's harmful ultraviolet (UV) radiation, preventing it from reaching the Earth's surface. This UV radiation can cause skin cancer, cataracts, and other harmful effects on both humans and the environment. Therefore, stratospheric ozone plays a crucial role in protecting life on Earth by filtering out harmful UV radiation.Rate this question:
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- 17.
In a refrigeration system, the device that changes a low pressure vapor to a high pressure vapor is the:
- A.
Evaporator
- B.
Expansion device
- C.
Compressor.
- D.
Condenser
Correct Answer
C. Compressor.Explanation
The compressor in a refrigeration system is responsible for changing a low pressure vapor to a high pressure vapor. It does this by compressing the refrigerant gas, which increases its pressure and temperature. This high pressure vapor then moves to the condenser where it releases heat and condenses into a high pressure liquid. Therefore, the correct answer is compressor.Rate this question:
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- 18.
Data shows that chlorine in the stratosphere comes mainly from CFCs rather than from natural sources such as volcanoes because:
- A.
The rise in the amount of chlorine in the stratosphere matches the rise in the amount of fluorine, which has different natural sources than chlorine
- B.
The rise in the amount of chlorine in the stratosphere matches the rise in CFC emissions
- C.
Air samples taken from the stratosphere over erupting volcanoes show that volcanoes contribute a small quantitiy of chlorine to the stratosphere when compared to CFCs
- D.
All of the above.
Correct Answer
D. All of the above.Explanation
The correct answer is "All of the above" because the data shows that the rise in the amount of chlorine in the stratosphere matches the rise in the amount of fluorine, which has different natural sources than chlorine. Additionally, the rise in the amount of chlorine in the stratosphere matches the rise in CFC emissions. Furthermore, air samples taken from the stratosphere over erupting volcanoes show that volcanoes contribute a small quantity of chlorine to the stratosphere when compared to CFCs. Therefore, all of these factors indicate that chlorine in the stratosphere mainly comes from CFCs rather than from natural sources such as volcanoes.Rate this question:
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- 19.
Which atom of the CFC molecule causes ozone depletion?
- A.
Fluorine
- B.
Chlorine.
- C.
Sodium
- D.
Helium
Correct Answer
B. Chlorine.Explanation
Chlorine is the correct answer because CFCs (chlorofluorocarbons) contain chlorine atoms that are released into the atmosphere. These chlorine atoms then react with ozone molecules in the ozone layer, breaking them down and depleting the ozone. Fluorine is also present in CFCs, but it is the chlorine atoms that are primarily responsible for ozone depletion. Sodium and helium are not present in CFCs and do not contribute to ozone depletion.Rate this question:
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- 20.
The ozone layer protects the earth from:
- A.
Nuclear radiation
- B.
Infrared radiation
- C.
Ultraviolet radiation from the sun.
- D.
Bacteria from space
Correct Answer
C. Ultraviolet radiation from the sun.Explanation
The ozone layer acts as a shield, protecting the earth from harmful ultraviolet radiation emitted by the sun. This radiation can cause various health issues, including skin cancer, cataracts, and a weakened immune system. Without the ozone layer, these harmful rays would reach the Earth's surface, leading to widespread damage to both humans and the environment.Rate this question:
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- 21.
When using with any solvent, cleaner, chemical or refrigerant, you should review:
- A.
Moisture solubility information
- B.
Chemical compound reference sheets
- C.
Material safety data sheets.
- D.
Chemical composition reference sheets
Correct Answer
C. Material safety data sheets.Explanation
When using any solvent, cleaner, chemical, or refrigerant, it is important to review material safety data sheets (MSDS). These sheets provide important information about the potential hazards, handling instructions, and safety precautions associated with the substance. By reviewing the MSDS, you can ensure that you are aware of any potential risks and take the necessary precautions to protect yourself and others.Rate this question:
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- 22.
An award of up to what amount may be paid to a person supplying information that leads to a penalty against a technician who is intentionally venting?
- A.
$5,000
- B.
$10,000.
- C.
$27,000
- D.
$37,000
Correct Answer
B. $10,000.Explanation
The correct answer is $10,000. This means that a person supplying information that leads to a penalty against a technician who is intentionally venting may receive an award of up to $10,000.Rate this question:
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- 23.
The Montreal Protocol is:
- A.
An energy efficiency test developed by the Canadian government
- B.
A test procedure for measuring the level of chlorine in the stratosphere
- C.
A procedure or protocol to test for ozone concentration in the atmosphere
- D.
A treaty among nations that controls production of CFCs and HCFCs.
Correct Answer
D. A treaty among nations that controls production of CFCs and HCFCs.Explanation
The Montreal Protocol is a treaty among nations that controls the production of CFCs (chlorofluorocarbons) and HCFCs (hydrochlorofluorocarbons). This treaty was established to address the depletion of the ozone layer and reduce the release of harmful substances into the atmosphere. It aims to phase out the production and use of these ozone-depleting substances, promoting the use of safer alternatives. The Montreal Protocol has been successful in reducing the production and consumption of CFCs and HCFCs, contributing to the recovery of the ozone layer.Rate this question:
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- 24.
Which refrigerant is an HCFC?
- A.
R-123.
- B.
R-134a
- C.
R-410a
- D.
R-12
Correct Answer
A. R-123.Explanation
R-123 is the correct answer because it is a hydrochlorofluorocarbon (HCFC) refrigerant. HCFCs are a group of refrigerants that contain chlorine, fluorine, carbon, and hydrogen atoms in their chemical composition. R-134a, R-410a, and R-12 are not HCFCs but belong to other categories of refrigerants.Rate this question:
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- 25.
What is one of the most serious results of damage to the ozone layer?
- A.
Mutations of marine plants
- B.
Increased volcanic activity
- C.
Increases in human skin cancer.
- D.
Higher natural background radioactivity
Correct Answer
C. Increases in human skin cancer.Explanation
Damage to the ozone layer leads to increases in human skin cancer. The ozone layer acts as a shield, protecting the Earth from harmful ultraviolet (UV) radiation from the sun. When the ozone layer is damaged, more UV radiation reaches the Earth's surface, increasing the risk of skin cancer. UV radiation can damage the DNA in skin cells, leading to mutations and the development of cancerous cells. Therefore, the increase in human skin cancer is one of the most serious consequences of ozone layer depletion.Rate this question:
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- 26.
Of the refrigerants listed below, which has t he lowest ozone depletion potential?
- A.
R-22
- B.
R-11
- C.
R-12
- D.
R-113
Correct Answer
A. R-22Explanation
R-22 has the lowest ozone depletion potential among the refrigerants listed. Ozone depletion potential refers to the ability of a substance to deplete the ozone layer. R-22 is a hydrochlorofluorocarbon (HCFC) refrigerant, which has a lower ozone depletion potential compared to other chlorofluorocarbon (CFC) refrigerants like R-11, R-12, and R-113. HCFCs contain less chlorine atoms, which are responsible for ozone depletion, making R-22 a better choice in terms of environmental impact.Rate this question:
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- 27.
To determine the maximum allowable pressure to use when checking a system, check:
- A.
With the equipment owner
- B.
With the refrigerant pressure/temperature tables
- C.
The design pressure on the equipment nameplate
- D.
Ask the local utility company
Correct Answer
C. The design pressure on the equipment nameplateExplanation
To determine the maximum allowable pressure to use when checking a system, it is important to refer to the design pressure on the equipment nameplate. This is because the nameplate provides information about the manufacturer's intended operating limits for the equipment. By adhering to the design pressure specified on the nameplate, one can ensure that the system is not subjected to pressures that could potentially cause damage or safety hazards. Checking with the equipment owner, referring to the refrigerant pressure/temperature tables, or asking the local utility company may provide additional information, but the design pressure on the equipment nameplate is the most reliable source for determining the maximum allowable pressure.Rate this question:
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- 28.
Ozone depletion potential, or ODP, is:
- A.
Always equal to twice the global warming potential, or GWP.
- B.
An absolute rating of the health hazard caused by ozone depletion.
- C.
A measure of the ability of CFCs and HCFCs to destroy ozone.
- D.
A rating for ground level smog pollution.
Correct Answer
C. A measure of the ability of CFCs and HCFCs to destroy ozone.Explanation
ODP, or ozone depletion potential, is a measure of the ability of CFCs and HCFCs to destroy ozone. It quantifies the potential of these substances to deplete the ozone layer and contribute to ozone depletion. ODP is not always equal to twice the global warming potential (GWP) and is not directly related to the health hazard caused by ozone depletion or ground level smog pollution. Therefore, the correct answer is that ODP is a measure of the ability of CFCs and HCFCs to destroy ozone.Rate this question:
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- 29.
An example of an HFC refrigerant is:
- A.
R-12
- B.
R-22
- C.
R-123
- D.
R-134a
Correct Answer
D. R-134aExplanation
R-134a is an example of an HFC refrigerant. HFC stands for hydrofluorocarbon, which is a type of refrigerant that does not contain chlorine, making it less harmful to the ozone layer compared to other refrigerants like R-12 and R-22. R-123 is not an HFC refrigerant, but rather a halocarbon refrigerant. Therefore, the correct answer is R-134a.Rate this question:
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- 30.
Whenever dry nitrogen from a portable cylinder is connected to a system, what item is of most importance in consideration of safety?
- A.
The regulator has a new set of gauges.
- B.
The pressure gauges are clean.
- C.
There is a relief valve in the downstream line from the pressure regulator.
- D.
No refrigerant lines can leak.
Correct Answer
C. There is a relief valve in the downstream line from the pressure regulator.Explanation
The most important item in consideration of safety when connecting dry nitrogen from a portable cylinder to a system is the presence of a relief valve in the downstream line from the pressure regulator. This relief valve is crucial as it helps to prevent over-pressurization in the system. If the pressure exceeds the safe limit, the relief valve will open and release the excess pressure, ensuring the safety of the system and the individuals working with it.Rate this question:
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- 31.
During servicing of a refrigeration system containing R-12, the refrigerant must be:
- A.
Recovered
- B.
Recovered and replaced with R-134a, no exceptions!
- C.
Vented
- D.
Destroyed
Correct Answer
A. RecoveredExplanation
During servicing of a refrigeration system containing R-12, the refrigerant must be recovered. This means that the R-12 refrigerant should be safely collected and stored for proper disposal or recycling. It is important to recover the refrigerant to prevent its release into the atmosphere, as R-12 is a potent greenhouse gas that contributes to ozone depletion. Recovering the refrigerant ensures that it is handled in an environmentally responsible manner and reduces the impact on the ozone layer.Rate this question:
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- 32.
Which safety precaution(s) should be always followed:
- A.
Never apply an open flame to a refrigerant cylnder
- B.
Never cut or weld any refrigerant line when refrigerant is in the line
- C.
Never use oxygen to purge lines or to pressurize a system
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
All of the mentioned safety precautions should be always followed. Applying an open flame to a refrigerant cylinder can cause it to explode or release toxic gases. Cutting or welding a refrigerant line while the refrigerant is still in the line can also lead to explosions or the release of harmful substances. Using oxygen to purge lines or pressurize a system can result in combustion or explosion hazards. Therefore, it is crucial to adhere to all of these precautions to ensure safety.Rate this question:
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- 33.
In a vapor compression refrigeration system, cooling occurs when:
- A.
Refrigerant liquid turns to vapor.
- B.
Refrigerant vapor turns to liquid.
- C.
The refrigerant is under maximum pressure.
- D.
The refrigerant gives off heat.
Correct Answer
A. Refrigerant liquid turns to vapor.Explanation
In a vapor compression refrigeration system, cooling occurs when the refrigerant liquid turns to vapor. This is because the refrigerant absorbs heat from the surroundings as it evaporates, causing the temperature of the surroundings to decrease. The vaporized refrigerant then travels to the compressor where it is compressed, raising its temperature and pressure. This high-pressure vapor is then condensed back into a liquid state, releasing heat to the surroundings. However, the primary cooling effect in the system occurs during the phase change from liquid to vapor.Rate this question:
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- 34.
The evacuation of a system is a method of:
- A.
Pinpointing the location of leaks.
- B.
Acid removal.
- C.
Dehydration.
- D.
All of the above.
Correct Answer
C. Dehydration.Explanation
The evacuation of a system refers to the process of removing air and moisture from the system. This is typically done using a vacuum pump. Dehydration is a crucial step in many systems as it helps to eliminate any moisture that may be present. Therefore, the correct answer is dehydration, as it encompasses the removal of air and moisture from the system.Rate this question:
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- 35.
Each chlorine atom in the stratosphere can destroy ___ ozone molecules.
- A.
100
- B.
1,000
- C.
10,000
- D.
100,000
Correct Answer
D. 100,000Explanation
Each chlorine atom in the stratosphere has the potential to destroy 100,000 ozone molecules. This is because chlorine atoms act as catalysts in the destruction of ozone molecules. When a chlorine atom reacts with an ozone molecule, it forms chlorine monoxide (ClO) and oxygen. The chlorine monoxide can then react with another ozone molecule, forming more oxygen and regenerating the chlorine atom to continue the cycle. This process allows a single chlorine atom to destroy a large number of ozone molecules, leading to the depletion of the ozone layer.Rate this question:
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- 36.
An example of an HFC refrigerant is:
- A.
R-11
- B.
R-124
- C.
R-142b
- D.
R-410a
Correct Answer
D. R-410aExplanation
R-410a is an example of an HFC refrigerant. HFC stands for hydrofluorocarbon, which is a type of refrigerant that does not contain chlorine. R-410a is a blend of two HFC refrigerants, namely difluoromethane (R-32) and pentafluoroethane (R-125). It is commonly used in residential and commercial air conditioning systems as a replacement for older refrigerants that contribute to ozone depletion. R-410a is considered more environmentally friendly and has a higher cooling capacity compared to other refrigerants.Rate this question:
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- 37.
Which gas(es) would cause the LEAST damage to the environment during a leak check?
- A.
Dry nitrogen and R-22
- B.
Dry nitrogen and R-12
- C.
Compressed air and R-12
- D.
Dry nitrogen
Correct Answer
D. Dry nitrogenExplanation
Dry nitrogen would cause the least damage to the environment during a leak check because it is an inert gas that does not contribute to ozone depletion or global warming. R-22 and R-12 are both refrigerants that are known to be ozone-depleting substances and have a high global warming potential. Compressed air, although not specified in the answer choices, may contain moisture and other contaminants that could be harmful to the environment. Therefore, dry nitrogen is the best choice for minimizing environmental damage during a leak check.Rate this question:
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- 38.
Refrigerant migrates to the compressor crankcase because of a difference in __________ between the refrigerant and the oil.
- A.
Vapor pressure
- B.
Acidity
- C.
Volume
- D.
Density
Correct Answer
A. Vapor pressureExplanation
Refrigerant migrates to the compressor crankcase because of a difference in vapor pressure between the refrigerant and the oil. When there is a difference in vapor pressure, the refrigerant tends to move from an area of higher pressure to an area of lower pressure. In this case, the refrigerant moves from the refrigeration system to the compressor crankcase where the pressure is lower, causing the migration.Rate this question:
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- 39.
Which refrigerant is an HCFC?
- A.
R-22
- B.
R-134a
- C.
R-410a
- D.
R-12
Correct Answer
A. R-22Explanation
R-22 is the correct answer because it is an HCFC (hydrochlorofluorocarbon) refrigerant. HCFCs contain chlorine, which contributes to the depletion of the ozone layer. R-22 was commonly used in air conditioning and refrigeration systems, but it is being phased out due to its harmful environmental effects.Rate this question:
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- 40.
It is important not to mix R-22 and R-410A refrigerants in the same container because:
- A.
The mixture may be impossible to reclaim.
- B.
The mixture will explode.
- C.
The mixture is corrosive.
- D.
They use different oils.
Correct Answer
A. The mixture may be impossible to reclaim.Explanation
Mixing R-22 and R-410A refrigerants in the same container may result in a mixture that is difficult or impossible to reclaim. This is because these two refrigerants have different chemical compositions and properties, and mixing them can lead to the formation of a new substance that cannot be easily separated or processed. As a result, the mixture may need to be disposed of, leading to wastage and potential environmental harm. It is therefore important to avoid mixing these refrigerants to ensure proper handling and disposal.Rate this question:
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- 41.
When using recovery unit, the fill level of the recovery tank can be controlled by:
- A.
A mechanical float switch.
- B.
An electronic shut-off device.
- C.
Weight.
- D.
All of the above.
Correct Answer
D. All of the above.Explanation
The correct answer is "all of the above" because the fill level of the recovery tank can be controlled by a mechanical float switch, which detects the level of the liquid and triggers a shut-off mechanism when it reaches a certain point. An electronic shut-off device can also be used to automatically stop the filling process when the desired level is reached. Additionally, the weight of the recovery tank can be monitored to determine its fill level, with a decrease in weight indicating that it is being filled. Therefore, all three options mentioned can be used to control the fill level of the recovery tank.Rate this question:
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- 42.
Which of the following refrigerant releases is a violation of the EPA prohibition on venting?
- A.
Release of "de minimis" quantities in the course of making good faith attempts to recover refrigerant.
- B.
Release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully charged appliance to "leak-check" the appliance
- C.
Refrigerants emitted in the course fo normal operation of an appliance
- D.
"de minimis" refrigerants vented when connecting or disconnecting self-sealing hoses to charge a unit
Correct Answer
B. Release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully charged appliance to "leak-check" the applianceExplanation
The release of mixtures of nitrogen and refrigerant that result from adding nitrogen to a fully charged appliance to "leak-check" the appliance is a violation of the EPA prohibition on venting. This is because the EPA prohibits the intentional release of any refrigerant, including mixtures, into the atmosphere. Adding nitrogen to a fully charged appliance for leak-checking purposes and subsequently releasing the mixture would result in the venting of refrigerant, which is a violation of the EPA regulations.Rate this question:
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- 43.
Which of the following human health effects could result from an increase in ultraviolet radiation?
- A.
An increase in cataracts cases
- B.
An increase in male infertility cases
- C.
An increase in heat prostration with the elderly
- D.
An increase in the number of thyroid disorders
Correct Answer
A. An increase in cataracts casesExplanation
An increase in cataract cases could result from an increase in ultraviolet radiation. Ultraviolet radiation can damage the lens of the eye, leading to the development of cataracts. Cataracts cause clouding of the lens, leading to blurry vision and eventually vision loss if left untreated. Therefore, an increase in ultraviolet radiation could potentially lead to a higher prevalence of cataracts in the population.Rate this question:
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- 44.
Never use an open flame to heat a refrigerant tank because:
- A.
It can result in venting refrigerant to the atmosphere.
- B.
The tank may explode, causing serious injury to people nearby.
- C.
Refrigerant in the tank may decompose, forming a toxic material.
- D.
All of the above.
Correct Answer
D. All of the above.Explanation
Using an open flame to heat a refrigerant tank can have several dangerous consequences. Firstly, it can cause the refrigerant to vent into the atmosphere, leading to environmental pollution. Secondly, the heat from the flame can potentially cause the tank to explode, resulting in serious injuries to anyone nearby. Lastly, the high temperature from the flame can cause the refrigerant inside the tank to decompose, forming toxic materials that can be harmful to humans. Therefore, all of the above reasons explain why using an open flame to heat a refrigerant tank is not recommended.Rate this question:
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Mar 22, 2023Quiz Edited by
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Dec 07, 2012Quiz Created by
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