What role do fuses play in aircraft electrical systems?

Fuses are crucial components in aircraft electrical systems, primarily serving the purpose of protecting circuits from overcurrent conditions. When an electrical fault occurs, such as a short circuit or an overload, excessive current can flow through the circuits, potentially leading to overheating and damage to the wiring and components. A fuse is designed to break the circuit when the current exceeds a specified limit, effectively interrupting the flow of electricity and preventing further damage.

This protective mechanism ensures the safety and reliability of the aircraft's electrical systems by minimizing the risk of heat-related fires or failures. Fuses are calibrated to respond quickly to overcurrent situations, providing an essential safety feature in aircraft design.

The other options do not accurately represent the function of fuses in electrical systems. For example, fuses do not increase voltage or stabilize electrical output, nor are they used to measure electrical pressure (voltage). Rather, they focus solely on safeguarding the system against excessive current, making option B the correct choice.