Question

if we pass the current for a longer time what will happen to the resistance how should we avoid it

Answer 1

Of course it varies with the material used for the resistance. Passing current for a long time produces heat. If it cannot dissipate the heat generated, the device gets hotter which causes the resistances in most materials to increase. 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 thing which mainly affect a wire’s resistance (A conductor’s resistance) is the substance the wire made of. The substance’s quality which plays the major role here is the quality of the substance as being a conductor.

1) So to reduce resistance, the conductor must be made of pure copper or pure aluminum as they are good conductor of electricity.
2) the cross section area of the wire should be made more bigger which decreses the resistance.
3) temperature should be reduced or changed to a material that has a lower resistivity. Some metals will become super conductors at temperatures near absolute zero.