2nd Class Power Engineering (2B1) Practice Exam

Compression plays a significant role in the combustion process, particularly in internal combustion engines. When the air-fuel mixture is compressed, it results in a higher temperature and pressure within the combustion chamber. This increase in temperature and pressure contributes to more efficient combustion.

By speeding up combustion, compression allows for a more complete and thorough burn of the fuel. As the fuel ignites due to the heat generated by compression, the reaction occurs more rapidly. This rapid combustion can lead to improved engine performance, higher power output, and greater efficiency, as the energy stored in the fuel is converted to work more effectively.

The other options do not accurately describe the primary effect of compression on combustion. For instance, while increased fuel injection may happen in some systems, it isn't a direct result of compression alone. Likewise, creating a richer mixture refers to the fuel-to-air mixture's proportions rather than compression's effects. Lastly, compression does not inherently maintain engine temperature; it is more about optimizing the combustion process to maximize energy extraction from the fuel.