Electroscope; conceptual charge distribution questions

[jhb1422]

Hello all,

Q: If an electroscope is positively charged throughout (gold leaves are being repelled), and a very strong rod that is negatively charged, is progressively brought closer to the electroscope... How are the charges distributed?

I think that as the negatively charged rod is brought closer to the electroscope... the positive charges in the electroscope move towards the top, and the gold leaves will return to "rest."

However, if the rod is brought even closer (but not touching) to the electroscope... will the gold leaves be repelled again due to negative charge migrating down to the gold leaves?

Am I correct in my thinking on this one?


Q2: Consider a piece of aluminum foil near a negatively charged pen. While the pen is ner the foil, you touch the foil, then remove your finger. Then remove the pen.

I'm not completely sure about this one. Do the positive charges migrate towards the negative charge, and the negative migrate away... then when I touch the foil with my finger... do the negative charges move to my finger.. leaving the foil positively charged?

Thanks in advance. :)

 

[Vailanor]

Yes, that's correct. When you touch the foil with your finger, the negative charges will move to your finger and the foil will be left with a positive charge. When the negatively charged pen is removed, the positive charges will move back to the foil.