Which of the following indicates an overload condition in fuses?

A foggy fuse indicates an overload condition because when a fuse experiences excess current flow, the metal filament within can melt or vaporize, resulting in gas that creates a cloudy appearance within the fuse. This foggy look is a clear visual cue that the fuse has experienced a failure due to overheating, often due to an overload situation where the circuit is drawing more current than it is designed to handle.

In contrast, a clear fuse typically shows no signs of failure and is operational, while a bright or glassy fuse may refer to different conditions but does not specifically indicate an overload. Understanding these symptoms helps in identifying electrical issues and ensuring proper safety measures are taken when working with electrical systems.