Pre-ignition is defined as energy transfer from a gas to a fuel.

Pre-ignition is defined as energy transfer from a gas to a fuel.

• A. Energy transfer from a gas to a fuel.
• B. Energy transfer from a liquid to a gas.
• C. Ignition by spark.
• D. Backflow into potable water.

Answer: (A)

Pre-ignition happens when heat energy from the surrounding gas or hot surfaces is transferred to the fuel vapor, raising it to its ignition temperature before the intended ignition source fires. That energy transfer from a gas to a fuel is the key idea: the hot gas provides enough heat to cause the mixture to ignite prematurely. The other ideas describe different processes—the liquid turning into vapor (evaporation), ignition driven by a spark (normal ignition), or an unrelated backflow into potable water. So the option that defines energy transfer from a gas to a fuel best captures how pre-ignition occurs.

Pre-ignition happens when heat energy from the surrounding gas or hot surfaces is transferred to the fuel vapor, raising it to its ignition temperature before the intended ignition source fires. That energy transfer from a gas to a fuel is the key idea: the hot gas provides enough heat to cause the mixture to ignite prematurely. The other ideas describe different processes—the liquid turning into vapor (evaporation), ignition driven by a spark (normal ignition), or an unrelated backflow into potable water. So the option that defines energy transfer from a gas to a fuel best captures how pre-ignition occurs.