Question 18Motor Plants - Assistant Engineer

70% to pass

In the pressure-volume diagram, shown in the illustration, what occurs between points "e" and "f"? Illustration MO-0035

Diagram for USCG Motor Plants Assistant: In the pressure-volume diagram, shown in the illustration, what occurs between...
AThe exhaust valve closes.
BThe intake ports close.
CPressure in the cylinder decreases.
DVolume in the cylinder decreases.
AI Explanation

The correct answer is C) Pressure in the cylinder decreases. Between points "e" and "f" on the pressure-volume diagram, the exhaust valve is open and the piston is moving downward, causing the volume in the cylinder to increase. As the volume increases, the pressure in the cylinder decreases, as described by Boyle's law, which states that the pressure and volume of a gas are inversely proportional. The other answer choices are incorrect because: A) The exhaust valve closes after point "f", not between "e" and "f"; B) The intake ports close before point "e"; and D) The volume in the cylinder increases between "e" and "f", not decreases.

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