Temperature Dependence of the Conductors' Resistivity

As the temperature in metal wires increases, the amplitude of thermal motion of the atoms within the wires also increases, leading to a rise in electrical resistivity. This change in resistivity can be understood by examining the flow of current through the material, which is the movement of electrons from one atom (such as a copper atom) to another, driven by an electric field. In a metal, some electrons are free to move within the material's structure, and the flow of current occurs because of the movement of these free electrons. As the temperature rises, heat causes the atoms in the material to vibrate more intensely. The higher the temperature, the more vigorous these atomic vibrations become. These vibrations result in more frequent collisions between the free electrons and the bound electrons within the material. Each collision decreases the energy of the free electrons, which is the main factor contributing to increased resistivity. As the atoms vibrate more because of the higher temperature, the number of collisions rises, thereby increasing the material's resistance to the flow of electric current.