1
$\begingroup$

My question: At the very initial moment when the bird sits on the live wire, the bird and the live wire have a potential difference, which is normally of the magnitudes of $1000'$s. But why the current due to the charge build up build up doesn't kill the bird?

Okay, I have formulated my own theory for this. So please validate this too:

From google, the capacitance of human body is about $180pF-200pF$ and so birds should have a lesser value, since they are small. From this the charge build up in a human body would be(voltage of the live wire is $11kV$ in India)

$Q=180\times 10^{-12}\times 11000=0.00000198$

So such small charges cannot harm you.

$\endgroup$
3
  • $\begingroup$ More on birds on wires. $\endgroup$
    – Qmechanic
    Feb 5, 2017 at 12:40
  • $\begingroup$ @Qmechanic♦ I couldn't find anything about this. But regarding the birds issue maybe i will change the question to superman with bare foot on live wire :-p hehe $\endgroup$
    – Allen
    Feb 5, 2017 at 12:45
  • $\begingroup$ @Allen you are on the right track. Yes, there's initially a potential difference, but because of the low capacitance it very quickly subsides. Consider that a typical static electricity shock of a person walking across a carpet (in the winter time--when humidity is low) and touching grounded metal is on the order of several thousand volts, but its so brief it doesn't cause any damage to the person. $\endgroup$
    – Digiproc
    Feb 5, 2017 at 14:39

1 Answer 1

3
$\begingroup$

Answer by @Digiproc:

Yes, there's initially a potential difference, but because of the low capacitance it very quickly subsides. Consider that a typical static electricity shock of a person walking across a carpet (in the winter time--when humidity is low) and touching grounded metal is on the order of several thousand volts, but its so brief it doesn't cause any damage to the person.

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.