Why Magnetic Field?  

Your Q is so interesting and intelligent.I dont know why is that not answered yet.

1. Megnettic field is due to the mettals commonly.Mettals are highly reactive to make bonds and pass energy electrons.They have unpaired electrons in their outer shells.

When a mettal is under current then it follows the least way to pass through it.and if by chance there exists any region that is partial clos to the oter end but not any mettal path there.then some of current starts folloing through air.It reacts as Megnettic field.[e.g. in U shape mettal fluxing is more bettween heads].

2.it acts as an obstacle to those matters whicch have any unpaired electron in outer shell,or having conductor properties so that they could pass the charge.

3.Reason for earths magnetism is its core.in its core there are heavy metals in melt state revolving with its rotation and this rotation is making them to interchange of the charge contineously.This charge is responsible for our earths magnetism.

4.I am not sure abt it but may be a stick magnet got from nature contains highly charged compressed elements as occuer in earths core.they are so dense hence contains contineouse charge reducing to automosphere.when any thing reactive comes to their charg emmitting region that starts gaining electrons and gets stuck to it.


This post is really amazing...!!
Nice BRO!