What is the primary purpose of a fuse in an electrical circuit?

The primary purpose of a fuse in an electrical circuit is to protect the circuit from overcurrent. A fuse is a safety device that contains a thin wire or element that melts when the current flowing through it exceeds a certain level. This melting interrupts the circuit and prevents excessive current that could potentially lead to overheating, electrical fires, or damage to components in the circuit.

Fuses are designed to be a weak point in the circuit; they will fail before any other components (like wires, resistors, or motors) are subjected to harmful conditions. When the fuse blows, it effectively breaks the circuit, stopping the flow of electricity and protecting both the circuit components and the overall integrity of the electrical system.

The other options represent functions that are not related to the purpose of a fuse. They involve increasing voltage, converting power types, or amplifying signals, none of which pertain to the protective role that a fuse plays in ensuring safe operation of electrical circuits.