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Homework Help: About Wheatstone Bridge Method

  1. Apr 28, 2009 #1
    I need your help to finish my homework.I have only two questions

    1-If a diameter of a wire is doubled,what happens to its electicial resistivity?

    2-Why is different the resistivity of materials?

  2. jcsd
  3. Apr 28, 2009 #2
    What do you think?
  4. Apr 28, 2009 #3
    These questions arent that tough if take some time to look things up (such as the formula for electrical resistivity...)

    **whistles** http://en.wikipedia.org/wiki/Resistivity
  5. Apr 29, 2009 #4
    ok.I thought again and I understand the resistivity does not change.But I don't know any information about second question.I have looked wiki but I can't find any knowledge.Do you Help me
  6. Apr 29, 2009 #5
    How do metals conduct electricity?
  7. Apr 29, 2009 #6
    Hmm... I think you still have some work to do on number one.

    Look at the second equation down on the wiki page i posted
  8. Apr 29, 2009 #7
    Yes and it shows that resistance will change, not resistivity which is a property of the materal.


    So assuming q1 is written down correctly, what he said is fine.
  9. Apr 29, 2009 #8
    I understand the second question.İt's different because every material have different R,r,l,A

    Is it correct?
  10. Apr 29, 2009 #9
    the question asks why the resistivity changes.

    what you have stated does not show that.

    btw are you talking about resistivity or resistance in the orig question? Just making sure you are answering the right q.
  11. Apr 29, 2009 #10
    thank you so much brother I am really sure about it.My teacher gave me 100 points.Thank you again
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