At what percentage do the igniters and starter de-energize if fuel pressure is above 10 PSI?

When analyzing the operation of igniters and starters in relation to fuel pressure, it's crucial to understand the functioning of ignition systems in aerospace and industrial applications. If the fuel pressure is above 10 PSI, the de-energization of the igniters and starter typically occurs at a specific threshold.

In this context, the correct choice indicates that the igniters and starter are designed to automatically deactivate at 50% power when the fuel pressure reaches or exceeds 10 PSI. This mechanism ensures efficiently transitioning to a stable operating condition, where the fuel is adequately pressurized to support combustion without the need for continued ignition or starting assistance.

The 50% threshold is a critical calibration in these systems, serving not only to enhance safety by preventing unnecessary sparking or potential ignition in an over-pressurized environment but also maximizing efficiency by reducing energy consumption once the necessary conditions for stable combustion are met. This aspect becomes particularly essential during the operation of engines or turbines, where precise control over fuel and ignition systems directly impacts performance and safety.