ANS:A - Compression ignition system

The component not associated with the functioning of a petrol engine is the compression ignition system. Petrol engines, also known as gasoline engines, operate on the principle of the Otto cycle, which involves four strokes: intake, compression, power, and exhaust. In a petrol engine, the air-fuel mixture is ignited by a spark plug during the power stroke, leading to combustion and generation of power. The compression ignition system, on the other hand, is associated with diesel engines. In diesel engines, fuel is injected into the combustion chamber at high pressure, and ignition occurs due to the heat generated by the compression of the air in the cylinder, without the need for a spark plug. Therefore, the compression ignition system is not associated with the functioning of a petrol engine. The other components—spark plug, carburettor, and Otto cycle—are all integral to the operation of a petrol engine.