An electron moving in a wire collides again and again with atoms and travels an average distance between collisions that is called the mean free path. If the mean free path is less in some metals, what can you say about the resistance of these metals? For a given conductor, what can you do to lengthen the mean free path?

A substance with a short, medium, free path has improved electron flow resistance and a higher electrical resistance. Heat applications impose more molecular chaos on all materials and shorten the track further, increasing resistance of most materials. So, just refresh the material to expand the course. In certain materials, when cooled to the minimum temperature, the conductivity is substantially increased.