Identify which of the ff. object will be positive or negative charge

[Megaevelie]

Identify which of the ff. object will be positive or negative charge

1) Hand and Hair
2) PVC and Tetlon
3) Glass and Poly ester
4) Rubber and rubber
5) Hand and wood

 

[PeterO]

Identify which of the ff. object will be positive or negative charge

1) Hand and Hair
2) PVC and Tetlon
3) Glass and Poly ester
4) Rubber and rubber
5) Hand and wood

What technique is suggested? Look it up in a textbook?

 

[Megaevelie]

What technique is suggested? Look it up in a textbook?

I think Triboelectric series is the reference here. But I do not know what happens when both rubbers are rubbed. Is it possible that they both gain positive charges?