Rudolph's Heating And Air Conditioning! Trivia Quiz
Rudolph's review questions on air conditioning Chapter 50
Questions and Answers
- 1.
Refrigerant is a low-pressure liquid as it leaves the condenser.
- A.
True
- B.
Fale
Correct Answer
B. FaleExplanation
The given statement is false. Refrigerant is actually a high-pressure gas as it leaves the condenser, not a low-pressure liquid. The refrigerant absorbs heat from the surroundings in the evaporator and then is compressed in the condenser, which increases its pressure and temperature. After leaving the condenser, it enters the expansion valve where its pressure is reduced, causing it to become a low-pressure liquid. Therefore, the correct answer is "False" as the refrigerant is not a low-pressure liquid as it leaves the condenser.Rate this question:
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- 2.
The heater core may be plugged if the inlet hose feels hot and the outlet hose feels cold.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
If the inlet hose of a heater core feels hot while the outlet hose feels cold, it suggests that there is a blockage in the heater core. The hot coolant is not able to flow through the core and transfer heat to the air, resulting in a cold outlet hose. This can happen due to the build-up of debris or sediment in the core, which restricts the flow of coolant. Therefore, the statement is true.Rate this question:
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- 3.
The heater control valve is often called the water flow valve.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
The statement is true because the heater control valve is indeed commonly referred to as the water flow valve. This valve controls the flow of hot coolant from the engine to the heater core, which then allows the heater to produce warm air for the cabin. By regulating the flow of coolant, the heater control valve helps to control the temperature inside the vehicle. Hence, the statement is accurate.Rate this question:
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- 4.
A liquid will boil at a lower temperature when it is under pressure.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
This statement is false. A liquid will actually boil at a higher temperature when it is under pressure. This is because pressure raises the boiling point of a liquid by increasing the forces between its molecules, making it harder for them to escape into the gas phase. Therefore, higher pressure allows the liquid to reach a higher temperature before boiling occurs.Rate this question:
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- 5.
R-134a is a hydrofluorocarbon.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
R-134a is indeed a hydrofluorocarbon (HFC). Hydrofluorocarbons are a class of organic compounds that contain hydrogen, fluorine, and carbon atoms. R-134a, also known as 1,1,1,2-tetrafluoroethane, is a commonly used HFC in various applications, including as a refrigerant in air conditioning and cooling systems. It is preferred over other types of refrigerants due to its relatively low impact on the ozone layer. Therefore, the statement that R-134a is a hydrofluorocarbon is correct.Rate this question:
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- 6.
R-12 and R-134a refrigerants can be mixed.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
R-12 and R-134a refrigerants cannot be mixed because they have different chemical compositions and properties. Mixing them can result in decreased cooling efficiency, potential damage to the refrigeration system, and safety hazards. It is important to use the appropriate refrigerant specified by the manufacturer to ensure proper functioning and longevity of the system.Rate this question:
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- 7.
Mineral oil works well with R-12 refrigerant.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Mineral oil is a commonly used lubricant in refrigeration systems that use R-12 refrigerant. R-12, also known as dichlorodifluoromethane, is a chlorofluorocarbon (CFC) refrigerant that was widely used in older refrigeration and air conditioning systems. Mineral oil is compatible with R-12 and provides effective lubrication to the compressor and other moving parts of the system. Therefore, it is correct to say that mineral oil works well with R-12 refrigerant.Rate this question:
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- 8.
A thermostatic expansion valve is mounted on the outlet side of the evaporator.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
A thermostatic expansion valve is a device that controls the flow of refrigerant into the evaporator coil in an air conditioning or refrigeration system. It is designed to maintain a specific temperature and pressure by regulating the amount of refrigerant entering the evaporator. By being mounted on the outlet side of the evaporator, the thermostatic expansion valve can accurately sense the temperature of the refrigerant leaving the evaporator and adjust the flow accordingly. This positioning allows for precise control of the cooling process, making the statement true.Rate this question:
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- 9.
Aluminum tubing is often used to connect air conditioning components where flexibility is not required.
- A.
True
- B.
False
Correct Answer
A. TrueExplanation
Aluminum tubing is commonly used in air conditioning systems because it is lightweight, durable, and resistant to corrosion. It is often used to connect components where flexibility is not necessary, such as between the condenser and evaporator coils. This rigid tubing provides a reliable and efficient way to transport refrigerant and maintain the overall integrity of the system. Therefore, the statement "Aluminum tubing is often used to connect air conditioning components where flexibility is not required" is true.Rate this question:
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- 10.
Air conditioning systems that use an accumulator come equipped with a sight glass.
- A.
True
- B.
False
Correct Answer
B. FalseExplanation
Air conditioning systems that use an accumulator do not come equipped with a sight glass. A sight glass is typically found in systems that use a receiver/dryer, which is a different type of component used in air conditioning systems. The sight glass is used to visually inspect the refrigerant flow and detect any potential issues. Since accumulators and receiver/dryers serve different purposes in the system, it is not necessary for an accumulator-equipped system to have a sight glass.Rate this question:
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- 11.
On which of the following laws of nature is the air conditioning system based?
- A.
Heat flow
- B.
Heat absorption
- C.
Pressure and boiling points
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
The air conditioning system is based on the laws of nature related to heat flow, heat absorption, pressure, and boiling points. Heat flow is important in transferring heat from the indoor air to the outdoor environment, allowing for cooling. Heat absorption is necessary for the system to remove heat from the indoor air, making it cooler. Additionally, the system utilizes the principles of pressure and boiling points to change the state of the refrigerant, which helps in the cooling process. Therefore, all of the mentioned laws of nature play a role in the functioning of an air conditioning system.Rate this question:
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- 12.
Which of the following statements is correct?
- A.
Refrigerant leaves the compressor as a high-pressure, high-temperature liquid
- B.
Refrigerant leaves the condenser as a low-pressure, high-temperature liquid
- C.
Refrigerant returns to the compressor as a low-pressure, high-temperature vapor
- D.
None of the above
Correct Answer
D. None of the above -
- 13.
Which of the following statements is not correct?
- A.
The condenser is normally mounted in front of the radiator
- B.
The receiver/dryer is a storage tank for liquid refrigerant from the condenser
- C.
The accumulator is located between the condenser and the receiver/dryer
- D.
All of the above
Correct Answer
C. The accumulator is located between the condenser and the receiver/dryerExplanation
The correct answer is "The accumulator is located between the condenser and the receiver/dryer." This statement is incorrect because the accumulator is actually located between the evaporator and the compressor, not between the condenser and the receiver/dryer. The accumulator's main function is to collect any liquid refrigerant that may have escaped the evaporator and prevent it from entering the compressor, which could cause damage.Rate this question:
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- 14.
Which of the following may be electrically connected in series with the compressor electromagnetic clutch?
- A.
Ambient temperature switch
- B.
Thermostatic switch
- C.
Pressure cycling switch
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
All of the above components, including the ambient temperature switch, thermostatic switch, and pressure cycling switch, may be electrically connected in series with the compressor electromagnetic clutch. When these switches are connected in series, they allow for the control and regulation of the compressor's operation based on various factors such as ambient temperature, desired temperature, and pressure levels. This series connection ensures that all the switches work together to activate or deactivate the compressor electromagnetic clutch as needed, providing efficient and optimal functioning of the system.Rate this question:
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- 15.
Which of the following oils can be used in a R-134a system?
- A.
PAG oil
- B.
Natural oil
- C.
Castor oil
- D.
Mineral oil
Correct Answer
A. PAG oilExplanation
PAG oil can be used in a R-134a system because it is compatible with the refrigerant. PAG oil is specifically designed for use in air conditioning systems and is able to lubricate the compressor and other components effectively. It is also able to mix well with R-134a without causing any issues or damage to the system. Natural oil, castor oil, and mineral oil are not suitable for use in a R-134a system as they can cause compatibility issues and potentially damage the system.Rate this question:
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- 16.
A heating system includes all of the following parts except:
- A.
Heater core
- B.
Receiver/dryer
- C.
Ventilation system
- D.
Distribution plenum
Correct Answer
B. Receiver/dryerExplanation
A heating system is responsible for providing warmth in a space. The heater core is a crucial component that transfers heat from the engine coolant to the air that is blown into the cabin. The ventilation system helps distribute the heated air throughout the space. The distribution plenum is a duct that directs the airflow to different areas. However, the receiver/dryer is not directly related to the heating function of the system. It is a component of the air conditioning system that removes moisture and filters refrigerant, ensuring efficient cooling.Rate this question:
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- 17.
Which of the following statements is not correct?
- A.
The evaporator changes heated refrigerant to a liquid
- B.
Automatic temperature controls maintain a set passenger compartment temperature
- C.
Air conditioning/heater systems can be computer controlled
- D.
Heaters and air conditioners use the same plenum chambers
Correct Answer
A. The evaporator changes heated refrigerant to a liquidExplanation
The evaporator does not change heated refrigerant to a liquid. It actually changes the liquid refrigerant into a gas by absorbing heat from the air inside the passenger compartment. The condenser is responsible for changing the heated refrigerant gas back into a liquid.Rate this question:
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- 18.
Heater control valves are operated by a:
- A.
Cable
- B.
Thermostat
- C.
Vacuum motor
- D.
All of the above
Correct Answer
D. All of the aboveExplanation
The correct answer is "All of the above" because heater control valves can be operated by a cable, a thermostat, or a vacuum motor. These different mechanisms allow for different methods of controlling the flow of coolant to the heater core, depending on the specific design of the heating system.Rate this question:
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- 19.
Maximum air conditioning is not functioning properly. Technician A says the heater control valve could be faulty. Technician B says the recirculation door vacuum motor may be bad. Who is correct?
- A.
A only
- B.
B only
- C.
Both A and B
- D.
Neither A nor B
Correct Answer
C. Both A and BExplanation
Both Technician A and Technician B are correct. If the maximum air conditioning is not functioning properly, it could be due to a faulty heater control valve (as suggested by Technician A) or a bad recirculation door vacuum motor (as suggested by Technician B). Both of these components play a role in controlling the air conditioning system, so either one of them could be the cause of the issue.Rate this question:
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- 20.
Technician A says refrigerant leaves the compressor as a high-pressure liquid. Technician B says the condenser changes the high-pressure liquid refrigerant into a high-pressure vapor. Who is correct?
- A.
A only
- B.
B only
- C.
Both A and B
- D.
Neither A nor B
Correct Answer
D. Neither A nor BExplanation
Both Technician A and Technician B are incorrect. Refrigerant leaves the compressor as a high-pressure vapor, not a high-pressure liquid. The condenser then changes the high-pressure vapor into a high-pressure liquid.Rate this question:
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Mar 22, 2023Quiz Edited by
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May 03, 2009Quiz Created by
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