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Five hand rule

  1. May 23, 2005 #1
    What is the five hand rule?


    I need to know what direction the wire is going to move

    [N]

    I <--------

     
  2. jcsd
  3. May 23, 2005 #2
    Do you mean Left hand rule and right hand rule by any chance?

    Wire direction in a magnetic field is given by the Left hand rule.
    First finger = field direction
    Second finger = current direction
    Thumb = force direction.

    Make all three fingers perpendicular to each other. If you can't see how to do this, watch an Eminem video!!!
     
  4. May 23, 2005 #3

    Doc Al

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    Last edited: May 23, 2005
  5. May 23, 2005 #4
    Right hand rule?? Don't you mean left hand rule, or do we do this different in the UK?

    Left hand rule gives direction of the force on a wire in a magnetic field where the current direction is CONVENTIONAL current flow, not electron flow.

    In the case above, the wire moves OUT of the PC screen towards you.
     
  6. May 23, 2005 #5

    Doc Al

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    Looks like you do it differently. (I'm willing to use [itex]f[/itex] instead of [itex]\nu[/itex] for frequency, but don't mess with my right hand rule! :smile: )
    So does the right hand rule. I use the right hand rule whenever a cross product is involved. To find the direction of [itex]\vec{A}\times\vec{B}[/itex], just curl the fingers of the right hand from A to B along the shortest arc. The thumb points in the direction of the cross product. (At least that's the way I do it. Check the second of the links I posted for live action video of the right hand rule in use.)

    Apparently the right hand rule and your left hand rule give the same answer. Good thing, I suppose!
     
  7. May 23, 2005 #6
    The left hand and right hand rules are both taught in my school. We are taught to use the right hand rule for finding the directions of protons and the left hand rule for electrons (since the directions are opposite). However, the right hand rule is used primarily since the direction of the curled finger can just be made opposite if the particle is negative and the direction left the same if the particle is positive. They're interchangable methods, just depends on your preference. Here in the US it's standard to use the right hand, however.
     
  8. May 24, 2005 #7

    Danger

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    Again, a deficit of having never finished high school. I was taught only the left-hand rule. (ie: thumb in direction of current flow puts fingers in direction of magnetic field and vice versa) Jeez, but I love learning new stuff here!
     
  9. May 24, 2005 #8
    This is the LH Rule as we teach it:
     

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  10. May 24, 2005 #9

    EL

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    Could there be some mysterious connection between the "handrule" and which side of the road you drive on? :biggrin:
     
  11. May 24, 2005 #10
    No it doesnt, in the UK we drive on the correct side of the road, whilst you americans drive on the other side just because its the opposite of the english (do to the revolution etc...)
     
  12. May 24, 2005 #11

    EL

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    Well, that's exactly my "theory" you see...
    (left hand side-left hand rule,
    right hand side-right hand rule)

    Anyway, I thought it was well-known Sweden is not one of the united states of america. :wink:
     
    Last edited: May 24, 2005
  13. May 24, 2005 #12

    T@P

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    theres the all new (?) screwdriver rule for everyone that gets confused as to which hand is the right one. its the same basic idea, i.e. the thumb and fingers only point in one direction, instead of hand curling somewhere is which way you turn the screwdriver and the thumb direction is analogous to which way the screw you are screwing would go under that kind of rotation.

    this is really a difficult explanation of something very simple. and actually clockwise and c-clockwise is inherent if you want to know which way the screw goes, so you dont need to make funny hand symbols as you do it.

    oh and this ties in nicely with right tighty - lefty loosey ;)
     
  14. May 24, 2005 #13

    Danger

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    That works fine until you run into a left-hand thread and strip the thing.
     
  15. May 25, 2005 #14
    Clockwise is confusing too - if you are the clock!

    To a clock the hands go anti-clockwise.
     
  16. May 25, 2005 #15

    Danger

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    Not if it's dyslexic.
     
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