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I hope this is the right thread

  1. Dec 8, 2007 #1
    Well anyways..
    I'm currently a student at a High School.
    We have these "Scrap heap challenges"
    The idea of this one is to build a "Electromagnetic device"
    This one is to hold at least 5 grams of weight and maintain it..
    After that we keep adding weight to see who's can hold the most

    With the items of...[I'm unsure of some these item sizes but should be general area or somewhat close to that...And those are refering to width not length]

    Paper clips [Roughly 10]
    2 Dcell batteries
    1 1/4 inch steel bar
    1 1/2 inch steel bar
    1 inch steel bar
    1 1/4 inch aluminum bar
    1 1/2 wood [Wood is unsure type]
    2 hand cranks [This device has to circuit ends leading to clamp onto a device and you crank the handle producing an electric current] DC current btw..
    1 foot long tape
    5m of wire [the ampage im unsure of]

    I beleive this is most of the stuff used in experiment

    Any ideas or suggestions feel free ><
    This experiment should be similar to alot which I've also looked up online..but yea..
    Any help is helpful heh xD
    Thanks in advanced
  2. jcsd
  3. Dec 8, 2007 #2


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    Welcome to PF Filipino Rice.

    Which do you think would produce the most current (hence magnetic force); 2 D cell batteries or the hand crank generator? I would probably go for the generator and someone with a good arm.
  4. Dec 9, 2007 #3
    Thats personally what i thought too..
    We were trying to develop a way to connect them all in series to see if that would produce more current than a crank or battery alone.
    But personally we think the crank would produce more energy.

    As to the steel bars..
    We used the smallest one..and wrapped it with the wire..
    We were told more times it goes around the steel bar the more magnetic force it would produce..
    Correct me if im wrong ^^

    But thank you for welcoming me
  5. Dec 10, 2007 #4


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    Yes. The magnetic field, B, is proportional to (NxI)/R where N is the number of turns of your wire, I is the current from your generator, and R is radius of the loops. So to get a greater field; increase the the number of turns and electrical current through them, and make the loops small. Note: your electromagnet will have a smaller area of "pick-up" due to the smaller steel core.

    I think you should use only one hand crank generator since the current produced will depend on the speed in which the crank is turned. So you can't stop cranking.

    Good luck on the challenge. Let us know how it goes.
    Last edited: Dec 10, 2007
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