Question
If Y is grounded while the balloon is still close to X, which of the following will be true?
  1. Electrons will flow from the sphere to the ground
  2. Electrons will flow from the ground to the sphere
  3. Protons will flow from the sphere to the ground
  4. Protons will flow from the ground to the sphere.
<b>Figure 18.60</b> A positively charged balloon close to a neutral metal sphere.
Figure 18.60 A positively charged balloon close to a neutral metal sphere.
Question by OpenStax is licensed under CC BY 4.0
Final Answer

(b)

Solution video

OpenStax College Physics for AP® Courses, Chapter 18, Problem 16 (Test Prep for AP® Courses)

OpenStax College Physics, Chapter 18, Problem 16 (AP) video thumbnail

In order to watch this solution you need to have a subscription.

Start free trial Log in
vote with a rating of votes with an average rating of .
Video Transcript
This is College Physics Answers with Shaun Dychko. This sphere is initially neutral and a positively charged balloon is brought close to it causing a charge distribution because it will attract the electrons from the far side towards the close side— these electrons are attracted to the balloon— and leaving a positive charge behind on the far side of this sphere. Now we are told in this question that this far side is connected to ground so we have a wire going to ground and ground is considered to be an infinite sink or source of electrons. So being positively charged on this side is going to attract electrons from the ground to neutralize these positive charges and so the answer for this is (b): electrons will flow from the ground to the sphere.