What defines a short circuit?

A short circuit is defined by the phenomenon where electrical current takes an unintended path through a route that has lower impedance than the normal circuit. This often occurs when the conductive materials in the circuit make direct contact or are bypassed, providing a path with significantly less resistance. As a result, a large amount of current can flow through this unintended pathway, leading to overheating and potentially damaging components in the circuit, or even causing fires.

In the context of the other options:

A describes a proactive failure where power is intentionally lost due to a break in the circuit, which is not indicative of a short circuit.

C suggests that an increase in resistance leads to current loss, but a short circuit is characterized by a decrease in resistance and a surge in current flow.

D relates to current direction, which is unrelated to short circuits, as this condition focuses on unintended pathways rather than the direction of current flow.

Therefore, understanding a short circuit as a situation where current opportunistically flows through a less resistant route is essential for identifying and preventing potential hazards in electrical systems.