What is the primary function of fuses in electrical systems?

The primary function of fuses in electrical systems is to prevent overloads by breaking the circuit. Fuses serve as a safety device that protects electrical circuits from excessive current. When the current flowing through a fuse exceeds its rated limit, the fuse element melts or blows, effectively breaking the circuit and stopping the flow of electricity. This action helps prevent damage to electrical components and reduces the risk of fires caused by overheating or short circuits.

In contrast, the other options do not accurately describe the function of fuses. Enhancing circuit efficiency is not a role of fuses; they are designed primarily for protection rather than performance improvement. Providing additional power to circuits is the opposite of what fuses do, as they limit the flow of current rather than supply it. Regulating voltage levels is also not a function of fuses; this task is normally handled by other components such as voltage regulators or transformers. Therefore, the correct answer emphasizes the protective role of fuses in maintaining the safety and integrity of electrical systems.