Aux 2 Unit 10 Quiz 5

Correct Answer:
B) Low-pressure vapor

Explanation:
After absorbing heat in the evaporator, the refrigerant exits as a low-pressure vapor, ready to be compressed by the compressor.

Correct Answer:
D) Cooling tower

Explanation:
A cooling tower is used in water-cooled systems, not in direct expansion systems. DX systems typically consist of an evaporator, compressor, condenser, and expansion valve.

Correct Answer:
C) Both sensible and latent cooling

Explanation:
In the evaporator, the refrigerant absorbs both sensible heat (reducing air temperature) and latent heat (condensing water vapor in the air) to cool the air efficiently.

Correct Answer:
B) The refrigerant directly absorbs heat from the air and changes phase in the evaporator

Explanation:
In a DX system, the refrigerant flows directly through the evaporator coils where it absorbs heat from the air, changing from liquid to vapor. This direct heat exchange eliminates the need for an intermediate fluid.

Correct Answer:
B) The air cooler directs warm air over the evaporator coils where the refrigerant absorbs heat

Explanation:
The air cooler channels warm air over the evaporator coils, enabling the refrigerant to absorb the heat and cool the air.

Correct Answer:
C) It absorbs heat and changes from a liquid to a vapor

Explanation:
In the evaporator, the refrigerant absorbs heat from the air being cooled, causing it to evaporate and change from a liquid to a vapor.

Correct Answer:
B) To control and reduce the pressure and temperature of the refrigerant before it enters the evaporator

Explanation:
The expansion valve regulates the flow of refrigerant into the evaporator, reducing its pressure and temperature to allow effective heat absorption.

Correct Answer:
B) Direct cooling with high efficiency and simple design

Explanation:
A DX system provides efficient cooling with a straightforward design, as the refrigerant directly cools the air without intermediate fluids.