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What makes the best conductor

  1. Nov 17, 2015 #1
    I need some help with my science fair project question and I wanna know what metal it is honestly it has to be copper write that is what wires are made of?
     
  2. jcsd
  3. Nov 17, 2015 #2

    anorlunda

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    If cost is unimportant, silver and gold are better conductors than copper.

    But what is your definition of best?
     
  4. Nov 17, 2015 #3
    well least expensive and a good cunductor
     
  5. Nov 17, 2015 #4

    anorlunda

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    Aluminum is cheaper than copper and conducts well, but it is illegal in house wiring in USA building codes.

    Edit: Carbon conducts very well, but cheap forms of carbon don't bend well.

    Everything has advantages and disadvantages.
     
  6. Nov 17, 2015 #5
    Okay but something that is use-able cheap and a good conducter.
     
  7. Nov 17, 2015 #6

    anorlunda

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    Copper is popular because most people believe it is is best including all properties.
     
  8. Nov 17, 2015 #7
    Ohhhh ok sounds good thanks
     
  9. Nov 17, 2015 #8

    anorlunda

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    If you want a good grade on your project question, work harder of the question rather than looking for answers.
     
  10. Nov 17, 2015 #9
    ok thank you for the tips but i am only in fourth grade.:smile:thank you
     
  11. Nov 18, 2015 #10

    anorlunda

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    Fourth grade :eek: I'm impressed. Just remember, a good question is better than 10 answers to a poor question.
     
  12. Dec 2, 2015 #11
    well i am in fourth grade cats which means we are doing fifth grade sixth grade and fourth grade work maybe some seventh grade but i don't know.:smile::cool::oldlaugh::oldbiggrin::oldsmile:
     
  13. Dec 3, 2015 #12

    Averagesupernova

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    Actually aluminum is not illegal in the USA. Certainly not as a blanket statement.
     
  14. Dec 3, 2015 #13

    anorlunda

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    You are correct, my statement was overly broad. Here's what I found here. It is an interesting history.

    The NEC (National Electric Code) has required aluminum alloy conductors for branch-circuit wiring (12–8 AWG) since 1981. The Code never explicitly prohibited aluminum building wire; however, there was a period in the early 1970s when UL withdrew the listing for aluminum building wire and revised the listing to require aluminum alloy conductors. During this process, there was no listed aluminum building wire available except remaining stock. Today’s “new technology” aluminum building wire is made of AA-8000 series aluminum alloy.
     
  15. Dec 3, 2015 #14

    CalcNerd

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    To correct some misinformation:
    Best Normal conductor: Silver
    2nd Best: Copper
    3rd: Gold
    4th: Aluminum

    All metals are good conductors (unless oxidized ie rusted or tarnished). Even with a thin coating of oxidation, the metal can conduct if the charges can be induced (put on) the conductor below the oxidation layer ie tarnished silver still conducts electricity well.

    Gold is often the preferred conductor for electronics or at least plugs and junction points as it doesn't corrode/tarnish and always has a clean surface (only a few acids have any effect on gold vs all other conductors can rust or tarnish even in air).

    Aluminum is light and cheap, but has poor ductile characteristics and dissimilar thermal expansion compared to copper wire which lead to poor connections and installations. The poor connection would form over time, not as initially installed due to the aluminum expanding and contracting under the equipment lugs (screws) as the wire warmed up under current flow. This is similar to someone loosening the screw a quarter turn or more. Loose connections equal higher resistance which in turn equals higher temps equal loosing the lug up more until you have a very poor connection that gets very HOT and a fire ensues! Hence the bad reputation for using Aluminum, especially for branch circuits ie home wiring.
     
  16. Dec 3, 2015 #15
    Aluminium is common in overhead high-voltage cables because of its weight. It is then used with a steel core for strength.
     
  17. Dec 3, 2015 #16
    ok thank you so much for your help
     
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