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Q & A: Spherical monopole magnet?

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Most recent answer: 05/01/2011
Q:
Hi, I am proposing a simple way to create a magnet with single pole. Not being a physics/science graduate, this came out of interest of thinking only. Lets consider a sphere, which is hollow inside and has a thickness to it at the surface only. If i cut a certain segment and make it out of magnet, such that the surface outside is North pole and inside is South pole. Similarly rearrange the whole sphere to made of magnets pieces attached together, with all the outside surface as North pole and inside surface as South pole then do I get a Magnetic monopole? As the outside surface in the three dimension is a North pole. Is this feasible? Advance thanks for your replies and comments. Harish
- Harish (age 26)
India
A:
That's a very clear question. The magnetic field has a divergence of exactly zero, which means that the integral over the surface of the field component pointing outwards is exactly zero.The magnet you propose would be spherically symmetric. The only spherically symmetric field which obeys our condition is exactly zero.

A more general way to see this is that a monopole is an object with non-zero magnetic divergence. The divergence of combined fields is just the sum of the individual divergences. So there's no way to put together a bunch of non monopoles, each with zero divergence, to get something with non-zero divergence.

Mike W.

(published on 05/01/2011)

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