What does the term "short circuit" refer to in electrical systems?

The term "short circuit" refers to an accidental connection that allows electric current to bypass the normal pathways, often due to a fault in the circuit. This condition occurs when there is a low-resistance connection between two points in an electrical system, leading to an unintended path for the current. As a result, the current may flow in a manner that isn't intended by the design of the circuit, which can lead to excessive current flow in the affected parts of the system. This can cause overheating, equipment damage, or even fire hazards, making the understanding of short circuits crucial for safety in electrical system design and maintenance.

The other options describe different electrical phenomena but do not accurately define what a short circuit is. An increase in voltage refers to a change in electric potential, a complete disconnection describes an open circuit, and a temporary connection created by a switch refers to normal operation of a circuit rather than the unintended conditions of a short circuit.