Ferrofluid reacts wildly to shaped magnetic fields!  


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Teachable Topics:

  • Magnetic Field Lines

Theory:

Ferrofluid is a man-made substance that acts like a liquid magnet. It is composed of tiny particles of magnitite (about 10 nm in diameter). These particles are suspended in a soap-like surfactant that keeps them separated. They are then free to flow around and do fascinating things like form spikes along magnetic fields. So when the electromagnet is on, the entire drill bit should be magnetized and the ferrofluid should stick to it and form spikes. 


Apparatus:

  • Ferrofluid
  • Drill bit or screw (something that can be magnetized)
  • Electromagnet
  • Paper Towels
  • Pipette
  • Gloves

Procedure:

  1. Turn on the electromagnet and increase the voltage until the drill bit is magnetized. 
  2. Pour a small amount of ferrofluid into the container with the drill bit.
  3. Using the pipette, drop a few drops onto the top of the drill bit and watch as it forms into spikes.
  4. Try experimenting with the electromagnet at different strengths.