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Magnetic field in a rotating magnet

  1. Mar 16, 2010 #1
    the theory

    magnetic field is produced by moving electric charges
    the field is proportional to the quantity and velocity of those charges

    the velocity of electrons is about 1mm/s at 15A/mm~2 in copper

    the velocity of a cd spinning is about 1000RPM 6m/s 6000 times more the the speed of the electrons

    so if the electrons where to flow around a cd that is spinning at 6m/s the electrons should move at 6.001m/s and the field 6000 times stronger

    the setup

    a cd with copper wire wound around it (20windings) with two contacts (see picture) that are connected to a pc power supply at 12V results in about 2A.

    the screwdriver has a magnetic tip and rotates about 45deg when current is flowing throw the copper coil wile not spinning.

    the result
    the screwdriver moves exactly the same amount??!!!

    anyone has an idea? electron velocity not in the mm/s range?

    Attached Files:

  2. jcsd
  3. Mar 16, 2010 #2
    What happens to the protons when you spin the entire disc?
  4. Mar 17, 2010 #3
    the protons will create the opposite magnetic field and cancel out the field generated by the electrons. thank you!!!

    so a staticly charged spinning object should generate a magnetic field...

    i got a 7kV source (ignition coil from my car). let see if i can figure out in how many electrons that translates too in CD....
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