What it shows:
The magnetization of a ferromagnetic substance occurs in little jumps as the magnetic moments of small bunches of atoms, called domains, align themselves with the external field. We can actually "hear" the switching of these domains by amplifying the currents induced in a coil that surround the ferromagnetic material.
How it works:
We use two 10mH coils mounted back-to-back to cut out AC noise. The samples, listed in Fig.1 are in wire form, about 3-5cm in length and pushed through corks so they can sit...
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