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Right-Hand Rule (Magnetism)

  1. Nov 30, 2005 #1
    Suppose I use the direction of my hand to be velocity, the curling of my fingers to be the magnetic field, and my thumb to be the magnetic force.

    1.) Then, if a positive object is moving North, and the magnetic field is NE, where is the resultant force?

    2.) How about the Earth's magnetic field? If the velocity is South, where is the force? The bigger question: where is the magnetic field? Is it from the South pole to the North pole?
  2. jcsd
  3. Nov 30, 2005 #2

    Chi Meson

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    Whoa, Whoa Whoa!
    For the "Lorenz FOrce" right hand rule, do not curl your fingers.
    Your thumb is the direction of velocity of the positive charge,
    your index finger is the direction of the magnetic field,
    your palm points in the direction of the force.

    Your thumb can be at any angle from perpendicular with your finger, to almost parallel with your finger and the rule still works; the force will be greatest when B and v are perpendicular though.

    2) In Canada, the magnetic field is actually pointing nearly straight into the ground at an angle of about 70 degrees. The horizontal componant is pointing toward the north geographic pole.(THis of course means that the magnetic polarity of the geographic north pole is "south")
  4. Nov 30, 2005 #3
    By "curling fingers" i meant pointing your fingers (or your index finger) toward a specified direction.


    Regarding the second answer: So Earth's magnetic field is... north? I don't quite understand. If i had a velocity which is northwards, where is my force?
  5. Dec 1, 2005 #4

    Chi Meson

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    Compasses allign themselves with teh magnetic field that they are in. So if a compass needle points north, then the magnetic field lines point north.

    When moving in the same direction as a magnetic field line, a charged particle will feel no force.
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