The resistance of a metallic conductor at constant temperature depends on:
An electric current flows when free electrons move in one direction through a conductor, such as a metal wire.
The moving electrons can collide with the ions in the metal.
This makes it more difficult for the current to flow, and causes resistance.
The resistance of a long wire is greater than the resistance of a short wire because electrons collide with more ions as they pass through.
Resistance and wire length are directly proportional.