Why is a good fuse reading zero ohms when tested with an ohmmeter?

A good fuse reading zero ohms when tested with an ohmmeter indicates a complete circuit without resistance. This means that the conductive path through the fuse is intact and allows electricity to flow freely without any interruptions. A reading of zero ohms shows that the fuse has not blown, and thus it can effectively protect the circuit by ensuring that current flows as intended.

When testing a fuse, the goal is to ensure that there are no breaks or high resistance points that could affect circuit performance. If a fuse were to show any significant resistance or an infinite reading, it would indicate that the fuse is either blown or has developed a fault that could prevent it from performing its protective function. Therefore, a zero-ohm reading confirms that the fuse is functional and suited for its role in the electrical system.