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Practice Listening: Multiple Choice, Multiple Answers ID: #40094 Medium Air conditioners
Instructions ›
You will see a video about how air conditioners work. Listen to the recording and answer the question by selecting all the correct responses. You will need to select more than one response.

Transcript:

Air conditioners are heat exchangers. They take warm air from the room, blow it over cooling coils to remove the heat, and then return it to the room. The heat absorbed by the cooling coils is then blown outdoors. The transfer agent in this exchange is called a refrigerant, which moves between a gas state to a liquid state as it flows through the air. When a liquid becomes a gas, it absorbs heat, and when a gas is compressed into a liquid, it releases heat. Warm room air is drawn through a dust filter by a fan, then blown over the cooling coils, which circulate the refrigerant in this liquid state as the room air flows by the coils, it causes the liquid and the coils to evaporate, and in the process heat is absorbed by the refrigerant as it turns to gas. The cold air is blown back into the room. The refrigerant gas is then compressed, increasing its temperature to return to a liquid state. The refrigerant must give up. It's heat. The heat transfer is accomplished by having outdoor air blown through the condenser corals containing the compressed gas, thus cooling the gas and transforming it back to a liquid, which is then returned to the cooling coils.

Which of the following statements accurately describe the process and components involved in how air conditioners work?

* Click on the correct answers

Result:

AI explanationShows the answer. Tap to open.
Option 3: "A fan draws room air through a dust filter before it is cooled by the cooling coils."

Explanation: This option is correct as it accurately reflects the process described in the text. The text states that warm room air is drawn through a dust filter by a fan before being blown over the cooling coils. This aligns perfectly with the description of how air conditioners operate.

Option 1: "The refrigerant remains in a gas state throughout the cooling process."

Explanation: This option is incorrect because the text clearly states that the refrigerant moves between a gas state and a liquid state as it flows through the air. Specifically, it mentions that when a liquid becomes a gas, it absorbs heat, and when a gas is compressed into a liquid, it releases heat. Therefore, the refrigerant does not remain in a gas state throughout the process.

Option 2: "Warm air is cooled by being passed over heating coils before being returned to the room."

Explanation: This statement is incorrect as it contradicts the text. The text specifies that warm air is blown over cooling coils, not heating coils. The purpose of the cooling coils is to remove heat from the warm air, not to heat it. Thus, this option misrepresents the function of the coils.

Option 4: "The refrigerant transforms between a gas and a liquid state as it moves through the system."

Explanation: This statement is correct and is directly supported by the text. It explains that the refrigerant moves between a gas state and a liquid state as it flows through the air, absorbing and releasing heat in the process. This transformation is a key component of how air conditioners function.

Option 5: "The cooling coils use outdoor air to directly cool the room."

Explanation: This option is incorrect because it misrepresents the function of the cooling coils. The text indicates that the cooling coils are involved in the heat exchange process with the refrigerant and do not use outdoor air to cool the room directly. Instead, the cold air produced by the cooling coils is blown back into the room, which is a different process.

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