Demonstrates existence of magnetic domains.

To demonstrate the Barkhausen effect as evidence for the existence of magnetic domains.

Transformer in Cu shielding, Strong magnet, amplifier, speaker

The high impedance winding in a small transformer is connected through shielded cable to a high gain amplifier and speaker. For low level background noise the transformer is surrounded by a copper case except for a small window left in this shielding. With high gain in the amplifier a magnet moved past the window produces noticeable clicking in the speakers. Updated on: 06/12/13