What could signal a blown fuse in an electrical circuit?

A blown fuse in an electrical circuit typically results in devices connected to that circuit ceasing to function. This occurs because fuses are designed to protect the circuit by breaking the electrical connection when the current exceeds a certain level. When a fuse blows, it interrupts the flow of electricity, meaning devices that rely on that circuit for power will no longer operate.

The other options do not indicate a blown fuse effectively. For instance, if a circuit operates without interruption, it is a sign that the fuse is intact and functioning properly. Similarly, higher than normal voltage in a circuit might indicate other issues, such as a fault or malfunctioning component, but it does not specifically signal that a fuse has blown. Finally, if all indicator lights remain on, this suggests that power is still being supplied to the circuit, again pointing to the fuse being intact rather than blown.