I was testing out objects with magnets and I didn't understand what made the north pole different from the south pole. I thought the poles were made of different materials, but I realized it wasn't. Can someone tell me what factors differentiate the north from the south?
[Physics] What’s the difference between the north and the south pole on a magnet
magnetic fields
Best Answer
I would say the difference between the north and south pole of a magnet is analogous to the difference between the geographic north and south pole of a spinning ball (for example earth). There are two points on a rotating body where its axis of rotation intersects its surface. If we call one of these points "north pole" and the other "south pole" we can use the locations of these two points to specify the spin direction.
So do the magnetic north and south poles of a magnet also indicate the spin direction of anything? What does rotate inside magnets? In very simple terms, the electrons. An electron has a spin and this creates a magnetic field, the strength and direction of that magnetic field is described by the so called "spin magnetic moment". If most of them spin in the same direction, you get a net magnetic field. If they spin in different directions, they cancel each other out and you don't get a net magnetic field. So the magnetic north and south poles of a magnet indicate something like the average spin direction of the electrons in the magnet.
Note that this analogy also explains how new poles are created when you split a magnet and why no magnetic monopoles exist. If you split the rotating earth in half along the equator, then both halves would still spin in the same direction, so the top half would have a new geographic south pole at the bottom and the bottom half would have a new geographic north pole at the top. And for the monopole, we can't specify a direction by only giving one point. How would a body look like whose axis of rotation would only intersect it's surface once? Of course a real body like that cannot exist. This is completely analogous for magnets with magnetic spin direction.