Question

what is the cause of resistance offered by the metallic wire in the flow of current through it​

Answer 1

An electric current flows when electrons move 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.

Answer 2

This is so

Because of the ohm's law

Whenever the current is passes acrooss the conductor by creating potential diffrence(source of energy) resistence automatically produces..

Which try to become a stopper for the current and produces heat.....

Thank you (2nd paragraph not for this but you have to know about it)...