Electric Charges

Discussion in 'General Electronics Chat' started by dhokarikar, May 23, 2012.

  1. dhokarikar

    Thread Starter New Member

    May 23, 2012
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    When we rub two different objects and electron transfer occurs, what happens to the electrons that are transferred from one object to another? Putting it in different words, does the object that is charged remain so for ever?
     
  2. steveb

    Senior Member

    Jul 3, 2008
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    Electrons are definitely transferred, but forever is a long time. It is quite possible for the charge to be eventually removed. However, removing all the excess charge from a charged insulator is not all that easy to do without good knowledge and special effort, and random events may take a very long time to remove all of the excess charge.
     
  3. #12

    Expert

    Nov 30, 2010
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    At the top of the "Chat" page, upon which you posted this question, Ohm's Law for Noobies has a section about this. The displaced electrons eventually wander off to places nearby that have a lesser concentration of electrons.

    I've never heard of playing, "charge the comb" and finding it still charged the next day, but I have seen a TV picture tube knock a guy on his caboose a week after it was removed from the TV.
     
  4. steveb

    Senior Member

    Jul 3, 2008
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    Well, yes, it depends on how good of an insulator you have. Just as capacitors have leakage, a pure insulator with charge can leak the the charge away. But very good insulators can retain some of the charge for a long time. Remember that the charge got there by doing work (rubbing), and sometimes it takes more work (I'm not sure by what method) to remove all of it. This is an effect that deviates from a pure Ohm's law effect. A high concentration of charge will dissipate due to the high potential, but after that, a residual charge can often remain since there is not enough potential to move the charges through the insulator and off the object. The residual charge may be too small for us to notice. The balloon may no longer stick to the wall and the comb may not raise our hair up, but there can still be some charge present with very good insulators.
     
  5. crutschow

    Expert

    Mar 14, 2008
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    Even air, although it is a very good insulator, can provide a path for the discharge of static charges on an insulator over a long period of time.
     
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