A magnet is cut in half. Why does this not form a monopole, even though one half contains the original north pole and the other half contains the original south pole?

A magnet is cut in half. Why does this not form a monopole, even though one half contains the original north pole and the other half contains the original south pole?

• A. Each half becomes a monopole.
• B. Domains align to make a north and a south pole on both halves.
• C. The halves become unmagnetized.
• D. The poles cancel out.

Answer: (B)

Magnetism comes from many tiny magnetic domains that align to produce a net dipole, giving each magnet a north end and a south end. When you cut the magnet, you don’t remove one pole; you create new surfaces where the internal alignment can rearrange. The domains near the new surfaces reorient so that each piece still has regions pointing north and pointing south, effectively turning each half into its own magnet with both poles. Magnetic field lines form closed loops, so you don’t end up with an isolated pole anywhere. This is why the best explanation is that the domains align to create a north and a south pole on both halves.

Magnetism comes from many tiny magnetic domains that align to produce a net dipole, giving each magnet a north end and a south end. When you cut the magnet, you don’t remove one pole; you create new surfaces where the internal alignment can rearrange. The domains near the new surfaces reorient so that each piece still has regions pointing north and pointing south, effectively turning each half into its own magnet with both poles. Magnetic field lines form closed loops, so you don’t end up with an isolated pole anywhere. This is why the best explanation is that the domains align to create a north and a south pole on both halves.