A short circuit is caused when two or more uninsulated wires come into contact with each other, which interferes with the electrical path of a circuit. The interference destabilizes normal functioning of electricity flow. The resistance generates a lot of heat in the wires and can lead to a fire.

A short circuit exists when positive and negative terminals of a current connect on a low-resistance conductor. This contact causes more electrical energy to be produced within a short time. Since a short circuit can lead to unintentional fires, electrical devices are installed with fuses or circuit breakers to prevent the surge of destructive electrical energy.