The metal strip in an electrical fuse will melt from the heat caused by...

The metal strip in an electrical fuse melts due to high amperage demands. When an electrical circuit experiences a current that exceeds the rated capacity of the fuse, this increased flow of electrons generates more heat than the fuse can safely dissipate. The metal strip is designed to conduct electricity at normal levels, but when the amperage surges, it can reach a temperature where the metal's melting point is exceeded, resulting in the strip melting. This is a safety feature designed to protect electrical circuits and prevent potential hazards such as overheating or electrical fires.

Other options do not accurately represent the mechanism of action in a fuse. Excessive voltage, low current, or low voltage do not contribute to the melting of the fuse metal strip in the same manner that a high amperage situation does, as they either do not generate sufficient heat or fall outside the operational concern of the fuse's protective role.