Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Question about magnets and attraction

  1. Sep 17, 2013 #1
    what would happen if a small magnet was exactly placed by the middle of another larger magnet in a direction parallel to it and at a considerable distance ? will it be pulled to the south pole or to the north pole ?
    or will it be pulled down the middle such that the north pole of the smaller magnet is on the south part of the bigger magnet and vice versa ?
     
  2. jcsd
  3. Sep 17, 2013 #2

    davenn

    User Avatar
    Science Advisor
    Gold Member

    what's a considerable distance ??
    state something that is meaningful

    how about trying it yourself? buy a couple of bar magnets and experiment with them
    in the manner you have said and report back your findings :smile:

    Dave
     
  4. Sep 18, 2013 #3
    i apologize if my post was not meaningful enough , also here its very hard to find any place that sells magnets * other than fridge magnets *
    basically what i am trying to find out is whether attracted objects follow flux lines or not .
    i know iron fillings or magnets get lined up by the flux lines of strong magnets .
    but do attracted objects follow those flux lines ? or do they get attracted and move in a straight line ?
    if they don't follow flux lines then what is the difference between objects aligning themselves to the magnet and objects being attracted by the magnet ?
     
  5. Sep 18, 2013 #4
    Objects don't follow flux lines in the same way as the electric field, because the magnetic force is perpendicular to these lines, whereas the electric force is tangent to these lines.

    The magnetic force is felt by currents, and the force is perpendicular to the current direction AND the flux lines.

    The alignment of magnetised iron filings parallel to the magnetic flux lines is due to a slightly more involved interaction, rather than a simple current, the iron filings are all tiny magnetic dipoles. Essentially a magnetic dipole is a tiny current loop, so the interaction is fundamentally the same, and it turns out that this current loop experiences a force which tends to make each individual filing align with the field.

    Think of each one as a compass needle. There are no obvious currents in this needle, but it is still magnetised, which means the microscopic magnetic dipoles (i.e. current loops) are all pointing in the same direction.
     
  6. Sep 18, 2013 #5
    To really understand the physics, you need to study the definition of magnetisation, and its relation to the magnetic field. Ideally this would be learnt after you learn Maxwell's microscopic equations, which means vector calculus.

    Until then, all I can give are hand-wavey explanations based on current loops which I imagine are impossibly hard to conceptualise.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Question about magnets and attraction
Loading...