Question

exam lesson name: energy conversions
exam number: 700697rr
exam guidelines
exam instructions
question 18 of 20 :
select the best answer for the question.

1. which stage of internal - combustion engine operation does work by turning a crankshaft?

a. exhaust
b. intake
c. compression
d. power
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Explanation:

To solve this, we analyze each stage of an internal - combustion engine:

• Exhaust Stage (A): In this stage, the exhaust gases are expelled from the engine. It does not involve doing work to turn the crankshaft.
• Intake Stage (B): Here, the fuel - air mixture is drawn into the cylinder. This stage is mainly about filling the cylinder and does not do work to turn the crankshaft.
• Compression Stage (C): The fuel - air mixture is compressed. This stage is about increasing the pressure and temperature of the mixture and does not do work to turn the crankshaft.
• Power Stage (D): In the power stage, the ignition of the compressed fuel - air mixture causes a rapid expansion of gases. This expansion pushes the piston down, and the piston's motion is transferred to turn the crankshaft, doing work.

Answer:

D. Power