The Joule effect

When the electricity flows through a conductor, since it has a finite resistance, electric energy is converted to heat. The heat is generated when the conduction electrons transfer energy to the conductors atoms through collisions.

Joule heating is in some cases unwanted, and efforts are made to reduce it. However, many applications rely on Joule heating: cooking plates, electric heaters or irons. The National Electrical Code (regionally adoptable standard for the safe installation of electrical wiring and equipment in the United States) defines de section (thickness) of the wires depending on the current (amperes) and other factor like isolation, or number of wires packed in the cable. If the wire is too thin, the resistance is bigger and the more heat is generated. In this video the current is flowing through a single thin copper wire ....