What function does a spark plug serve in an engine?

A spark plug plays a crucial role in the operation of a gasoline engine by igniting the fuel-air mixture within the combustion chamber. Its primary function is to create a spark at the right moment, which ignites the compressed mixture, leading to combustion. This process generates the power needed to drive the engine.

The timing and effectiveness of the spark created by the spark plug are essential for optimal engine performance and efficiency. When the air-fuel mixture ignites at the right moment, it maximizes power output and minimizes emissions. Proper functioning spark plugs contribute to smoother engine operation and better fuel economy, while worn or faulty spark plugs can lead to misfiring and reduced engine efficiency.

The other functions mentioned in the options relate to different components or systems within the engine. For instance, fuel flow regulation is typically managed by the fuel injectors or carburetors, while engine temperature control is primarily handled by the cooling system, including the radiator and thermostat. Filtering fuel impurities is a function of the fuel filter, ensuring that only clean fuel reaches the engine for proper operation. Thus, the spark plug's specific role in igniting the fuel-air mixture is vital for the engine's overall functionality and performance.