What device is designed to open and disconnect a circuit in the event of excessive current?

A) fuse
B) power supply
C) wire
D) potentiometer

Fuse

A safety device consisting of a strip of wire that melts and breaks an electric circuit if the current exceeds a safe level.

Excessive Current

A current flow surpassing the designed or safe limit of an electrical circuit or device, potentially leading to overheating or damage.