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Big challenge for best engeneer

  1. Nov 15, 2009 #1
    hi :]

    i have a suprise for anyone who can solve my challenge:

    we have the korona voltage formula...
    http://img130.imageshack.us/img130/4859/aaae.jpg" [Broken]

    let's see who can give me the long way to it (from begining to end and can explain it).. since it's the final formula..

    only 3 people succeed so far

    i promise you won't be dissapointed :]

    good luck!
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Nov 15, 2009 #2
    Assuming you are talking about Corona (Partial Discharge)

    Can't give you the derived formula, but can give you a simplified formula.


    Vrms=60 hertz RMS corona start voltage in air at sea level

    t=thickness in inches

    Formula is a simplified equation from equation in the Book "Reference Data For Radio Engineers", "Fifth Edition".

    Formula is reasonably accurate for transformer using kraft paper or Nomex insulation.
  4. Nov 15, 2009 #3
    i had this answer a few times.. you are correct but the formula i asked is harder work it wouldn't be fair for other so i'm sry no hard feelings?:wink:

    but! if you will find the formula i askes it's 150% suprise for you and not 100% like for the others
  5. Nov 15, 2009 #4


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    Science Advisor


    You might have the wrong idea about why this Forum exists.

    It is a group of volunteers who try to help people who need help.

    It seems you already have your answer and want to see if anybody will jump through hoops for your amusement. I hope nobody does.
  6. Nov 16, 2009 #5
    no, i got it- i just wanted to give a challenge to everyone here.. makes things more fun and from the suprize i give you can trust me that a lot of ppl can learn a lot from.

  7. Nov 16, 2009 #6


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    Staff: Mentor

    As was said, that is not how the PF works. It would be too easy for students to post their homework problems as "challenges", and therby cheat on their homework.

    Thread locked.
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