Magnetic fields inside hollow magnets, are the poles reversed? In a hollow magnet, a cube for example, are the magnetic poles reversed or is that a myth? In other words, if you consider the magnet in the image is hollow, and you place a smaller cube magnet inside it, would the magnets prefer to orient themselves like in example 1 in the image at the bottom? Or, are the poles inside the hollow cube somehow reversed, such that the magnets prefer a reverse orientation, example 2?


Note, this question is slightly similar to a previously asked question, it is not intended as spam but as genuine interest.
 A: If we are truly considering a hollow magnet, then example 2 is the preferred view. This is because magnets are made up of dipoles: you cannot have just a south pole, there must be a north. So, if you have a south pole that you've hollowed out, then the inside of said south pole must be north, because you cannot break apart a magnet to only have a south pole. By hollowing out the magnet, you have created a northern surface on the interior of the south pole, and a southern surface on the interior of the north pole. Theoretically, both configurations will sometimes work based on symmetry, but the first example is an example of an unstable configuration, while the second is an example of a stable configuration. What this means is that if there is any slight perturbation on either the hollow magnet or the interior magnet, then both configurations will tend towards the second example. You'd have to place a magnet perfectly in the first example to get it to work. 
For any example that you wish to examine, you can apply the fundamental rule that magnets exist only as dipoles. If you'd like 
$$\nabla\cdot\vec{B}=0$$
is the second Maxwell's equation and is taken as the mathematical explanation for why there are no such thing as magnetic monopoles. Thus you cannot have a magnetic north pole without an attached magnetic south pole. If you cut a magnet directly across the N-S line, you will just be left with 2 smaller bar magnets with a north and a south pole. 
If you have a bar magnet that I will write simply as S-N, then what you actually have is a whole collection of tiny dipoles aligned S-N S-N S-N S-N S-N. You can see if you wish to hollow out the intertior, you need to remove a S-N pair, you cannot just remove an S or an N (in particular, you must remove a connected pair). 
