Read about permanent magnet | 11 Discussions | Page 1

  1. N

    Formula to calculate the pull force between a magnet and a steel plate

    i have a neobydium magnet of grade n40 , the diameter of magnet is 15mm and thickness is 10 mm , now i want to calculate the pull force between this magnet and a steel plate when there is no gap between them ; & in second case i want to calculate the pull force when i put a 0.15mm copper plate...
  2. M

    I Origins of magnetic fields from permanent static magnets versus current

    The videos from Veritasium explaining permanent static magnets and electromagnets were quite good I thought… But they have me a little confused with regard to the origins of magnetic fields generated by an electric current as opposed to a permanent static magnet from say iron. 1. An...
  3. T

    I Eddy Current Speedometer Experiment

    Trying to create an experiment that utilizes a motor driven shaft to measure the angular velocity of another shaft via eddy currents. We made a mock experiment that uses 8mm shafts, pillow bearings, and ceramic magnets from home depot, but don't see a torque on a non-ferrous metal attached to a...
  4. P

    I Forces between a Solenoid and an External Permanent Magnet

    What happens if I have a permanent magnet outside an ideal solenoid? Does the permanent magnet rotate until the system reaches an energy minimum in its magnetic fields? Or does the permanent magnet fail to rotate because the magnetic field of the solenoid does not reach the magnet? Wouldn't...
  5. DeathCheese

    Calculate force on Permanent Magnet near a Paramagnetic surface

    Hello all, new here but plan to stick around for a while. I am currently trying to make a sensor that can detect if a material below it is paramagnetic. I believe paramagnetic is the proper term, but it needs to detect if the force exerted by permanent magnet is above a certain threshold. The...
  6. xareu

    Work done by permanent magnets

    I recall that the energy stored in a magnetic field is half the volume integral of the dot product of magnetic field and flux density vectors (H and B). When you place a piece of iron near a magnet, it does a work by attracting it. If H is 0 (I think there is only the magnetic moment vector M...
  7. N

    Will ferromagnetic dust retain magnetism in molten aluminum?

    Curie temperature for magnetite is 858 C, for iron 1043 C. Duralumin melting point is about 630 C. Does this mean that if I take a small silicone mold, place a magnet underneath it, add ferromagnetic powder to the mold and then pour molten aluminum in, I will get the aluminum detail with...
  8. James O'Neill

    Magnetism in gears

    If you put magnets in a gear (like in an Internal Permanent Magnet motor), what effect would the gear's teeth have on the magnetic fields?
  9. J

    Commercial transformers for variable frequency & voltage

    I am looking to step up the voltage of a 3 phase PM generator which has variable AC output of 200 - 400 Vl-l, and 15 - 30Hz. I am looking for a step up ratio between 1:1.5 and 1:2, and need this transformer to be a commercial device. What i have been finding is that most commercial...
  10. L

    Lightest Strongest magnet I can buy

    Hi All, I am wanting to buy the lightest, strongest magnet I can. Can someone please direct me or give me guidance on this issue? I am requiring a magnetic field of >5000 surface gauss. Any links or direction would be terrific, Thanks in advance, Dale.
  11. S

    Magnetic anode for copper cathode battery

    Hello everyone from the Physics Forums, I'm doing a school project and I'm looking for a potential anode alloy that is ferromagnetic which I could use with a copper cathode. I'm making a battery and I have to use copper as my cathode mainly because I have made the cathode cells structured...