Which of the following is NOT one of the three most common circuit-protection devices in aircraft?

The choice of resistors as the answer highlights an important aspect of circuit protection in aircraft. Circuit protection devices are specifically designed to prevent overloads and protect electrical circuits from damage caused by excessive current. The three most common circuit-protection devices used in aircraft are circuit breakers, fuses, and current limiters, each serving a distinct function in safeguarding the electrical system.

Circuit breakers provide a resettable method to interrupt current flow when a fault occurs, allowing them to be easily restored after addressing the issue. Fuses also serve a similar purpose, but they are designed to break the circuit permanently when they melt due to excessive current, requiring replacement after an overload. Current limiters are devices that restrict the amount of current that can flow in a circuit, thereby preventing excessive current that could lead to circuit damage.

In contrast, resistors do not provide protection in the same way. They are used to control and limit the electrical current in a circuit based on their resistance value, but they do not disconnect the circuit or protect against overloads. Instead, resistors are primarily used for circuit function, like controlling voltage levels or current flow, rather than for safeguarding against faults. This fundamental difference in purpose underscores why resistors are not considered one of the primary circuit-pro