# Homework Help: Electron flow in insulators

1. Jul 26, 2012

### sgstudent

1. The problem statement, all variables and given/known data
From what we've learned, insulators are not able to allow electrons to pass through or exit through them (beside rubbing/friction). So if I have a negatively charged piece of cloth and move a negatively charged metal rod such that they touch, will they both become neutral? That being said can a charged cloth induce a charge on a neutral metal object by contact as shown here: http://www.google.com/webhp?client=ms-android-google&source=android-home

2. Relevant equations

None

3. The attempt at a solution
I don't think that it can happen as insulators cannot permit the flow of charge in their surface or on them. So they should only hold their charges even when there is contact with a conductor/insulator and if the conductor/insulator is of the opposite charge, then there will be contact but again no charge transfer. Is this correct? Thanks for the help!

2. Jul 26, 2012

### NoPoke

just because an insulator will not allow charge to flow does not mean that you cannot transfer charge from the surface of the insulator to another object and vice versa.

I can't see your image :(

3. Jul 27, 2012

### sgstudent

Hi I meant that a charged insulator eg positively charge plastic strip touches a metal object. Will there be a redistribution such that both the plastic strip get positively charged? The image is at the bottom where a negatively charged insulator touches a metal sphere in this link http://www.physicsclassroom.com/class/estatics/u8l1d.cfm

4. Jul 28, 2012

### NoPoke

charge on the surface of an insulator is not tightly bound to that insulator. There will be electrostatic attraction but the charge is happy to be attracted to other materials too. More than happy if it can get to a lower energy state.

5. Jul 28, 2012

### Dens

Answering your original question, you get negative and negative. They should repel