What will be the charge at Y (i.e., the part of the sphere furthest from the balloon)?
- It can be positive or negative depending on the material.
This is College Physics Answers with Shaun Dychko. This sphere is initially neutral and then a positively charged balloon is brought close to it— as shown in this picture— and the question is what charge will there be on this far-side of the metal sphere? So there will an induced charge distribution on the sphere because this positive charge here will attract electrons from the far side towards the close side so these electrons are going to be attracted to the balloon on this side and the atoms that they left will become positively charged because they will be missing those electrons that were there before that have now moved to the near side. So the answer to this is positive: the charge at location Y is positive.