Eh-5 The Barkhausen Effect
Aim
To demonstrate the sudden alignment and realignment of the magnetic domains in a magnetic core.
Apparatus
- Barkhausen coil
- PA Amplifier and speaker
- Strong Bar Magnet
- Magnetic core material
- High Pass Filter
Barkhausen Effect Setup.
Description
A coil with thousands of turns of wire surrounding a core of magnetic material is connected to a PA Amplifier. The signal from the coil passes through a high pass filter prior to going to the amplifier. When a magnet is moved close to the core the rearrangement of the magnetic domains causes the distinctive Barkhausen sound to be heard. If the core is replaced with an aluminium bar no Barkhausen sound is heard.