What is the backup source of power for the No. 2 Inverter?

The backup source of power for the No. 2 Inverter is the Emergency Bus. This is because the Emergency Bus is designed to provide power to critical systems when the primary power sources are not available or fail. In aviation systems, especially in aircraft, inverters convert DC power to AC power and critical systems often rely on these powered inverters to maintain functionality during emergency scenarios.

When the No. 2 Inverter's primary power source is compromised, the Emergency Bus steps in to provide the necessary electricity to ensure essential systems continue to operate, supporting the safety and operability of the aircraft during flights. This function is integral to maintaining operational integrity and crew safety.

In contrast, other options like the Main Generator, Battery Charge Bus, and Ground Power Unit do not serve as direct backup sources for the No. 2 Inverter in the context of providing emergency power. The Main Generator is typically used as the primary source of power, while the Battery Charge Bus is intended for charging and not specifically for powering the inverter. The Ground Power Unit is used when the aircraft is on the ground and provides initial power but does not substitute for emergency power in-flight conditions.