Question 6 MODE02 - Assistant MODU Engineer

The Correct Answer is A **Explanation for Option A (Ignition delay):** Ignition delay (or ignition lag) is precisely defined as the time interval that elapses between the start of fuel injection into the combustion chamber (or engine cylinder) and the measurable start of combustion (ignition). During this delay, the injected fuel must atomize, vaporize, mix with air, and reach the necessary chemical and physical conditions for self-ignition to occur. **Explanation for Option B (Afterburning ratio):** Afterburning refers to the combustion that continues after the main flame front has passed, often occurring in the exhaust system (e.g., in gas turbines or jets). The term "Afterburning ratio" relates to the amount or efficiency of this process, not the delay before initial ignition. **Explanation for Option C (Turbulence lag):** "Turbulence lag" is not a standard or recognized technical term describing a specific time period in the combustion cycle. While turbulence is crucial for rapid mixing and faster combustion, this phrase does not define the time between injection and ignition. **Explanation for Option D (Injection lag):** Injection lag (or injection timing lag) typically refers to the slight mechanical or hydraulic delay between the command signal to inject fuel and the actual moment the fuel begins exiting the injector nozzle. While it is a time delay related to injection, it is the delay *in* the injection process itself, not the combustion delay that occurs *after* injection has started.