Which of the following is a safeguard for the ERJ's electrical system?

Circuit breakers serve as an essential safeguard for the ERJ's electrical system. They automatically interrupt the flow of electricity in the event of an overload, short circuit, or fault, preventing damage to electrical components and reducing the risk of fire. This mechanism allows for quick restoration of circuits without the need for replacement, as they can be reset after the fault condition has been cleared.

Diodes do play important roles in electrical systems, such as directing current flow and preventing backflow, but they are not specifically designed as safety devices for overcurrent situations. Fuses also act as protective devices by melting to break the circuit when excessive current flows, but unlike circuit breakers, fuses need replacement after they are activated. Transformers, on the other hand, are used to change voltage levels in electrical circuits and do not provide protection against overcurrent or faults.

Thus, the use of circuit breakers is critical in the ERJ's electrical system for maintaining operational safety and integrity.