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Three dielectric slabs in a capacitor

  1. Feb 13, 2016 #1
    di.jpg

    My textbook says this makes three pairs of parallel capacitors.
    I don't understand how?To make three pairs of parallel plates capacitors we at least need four plates but here we have only two
    plates.png
     
  2. jcsd
  3. Feb 13, 2016 #2

    cnh1995

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    You can insert metal plates at the boundaries of two dielectrics. They will be equipotential. Then splitting each plate into two plates in series, you can have 6 plates i.e. 3 capacitors.
     
  4. Feb 13, 2016 #3
    I think we need only four plates to form three parallel plate capacitors.
     
  5. Feb 13, 2016 #4

    cnh1995

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    Yes. But to distinguish three separate capacitors, you can make six plates from them.
     
  6. Feb 13, 2016 #5
    So we do need to insert metal plates there otherwise it is not possible to have 3 pairs of capacitors.

    pair.png
    Here I have shown green and orange metal plates placed at boundaries of dielectric slab . The left most and the right most plates were already there.
     
  7. Feb 13, 2016 #6

    cnh1995

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    Even if you don't insert plates, still it is a 3 capacitors in series combination.
     
  8. Feb 13, 2016 #7
    How?That is all my OP about.
     
  9. Feb 13, 2016 #8

    SammyS

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    How _____what_____ ?
     
  10. Feb 13, 2016 #9
    To make three pairs of parallel plates capacitors we at least need four plates.
     
  11. Feb 13, 2016 #10

    cnh1995

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  12. Feb 13, 2016 #11

    SammyS

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    See post #2.

    What is he not clear about.
     
  13. Feb 13, 2016 #12
    He is also talking about inserting metal plates .
     
  14. Feb 13, 2016 #13

    cnh1995

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    See mentor NascentOxygen's post #14 in that thread.
     
  15. Feb 13, 2016 #14
    At that time also I was having same doubt. But I tried to focus on different aspect of that problem.
     
  16. Feb 13, 2016 #15

    SammyS

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  17. Feb 13, 2016 #16

    cnh1995

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    What is not clear about that post?
     
  18. Feb 13, 2016 #17
  19. Feb 13, 2016 #18
    I don't understand how is it relevant to being "equipotential"?
     
  20. Feb 13, 2016 #19

    SammyS

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    Do you see that each boundary between the dielectric slabs is an equipotential surface?
     
  21. Feb 13, 2016 #20
    No. Is it perpendicular to electric field lines ?
     
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