What happens to the Electrical Potential the closer we are to a point charge?

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Discussion Overview

The discussion revolves around the behavior of electrical potential in relation to a point charge, particularly as one approaches the charge. Participants explore the implications of the mathematical expression for potential and the physical realities that accompany it.

Discussion Character

  • Exploratory
  • Technical explanation
  • Conceptual clarification
  • Debate/contested

Main Points Raised

  • One participant notes that the potential for a point charge approaches infinity as the distance to the charge decreases, leading to confusion about the implications of this behavior.
  • Another participant agrees that the potential does indeed go toward infinity and questions what this means for another charge approaching the point charge.
  • A participant suggests that the potential would be stronger as another charge gets closer, expressing uncertainty about how potential can approach infinity.
  • One participant emphasizes that the mathematical expression cannot be applied when the distance is zero, suggesting that physical constraints prevent charges from being at the same point.
  • Another participant points out that the mathematical model breaks down when considering the finite sizes of charged objects, indicating that Coulomb's law is not applicable at very small distances.

Areas of Agreement / Disagreement

Participants generally agree that the potential approaches infinity as one gets closer to a point charge, but there is uncertainty about the implications of this behavior and the limitations of the mathematical model. Multiple perspectives on how to interpret these results are present.

Contextual Notes

Participants highlight limitations in applying Coulomb's law at very small distances, particularly when considering the physical sizes of charges, which introduces additional complexities not accounted for in the basic formula.

Who May Find This Useful

This discussion may be of interest to students and enthusiasts of physics, particularly those exploring concepts of electric potential and the behavior of point charges in electrostatics.

SebastianRM
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So I have been wondering:
The potential for a point charge at the origin, is described as:
(Using the reference point at infinity): V=1/(4πε) * q/r
My question is, what happens to this Potential the closer we are to the point charge, and so the closer we would get, the Potential seems to go towards infinity, which does not make sense, so I would like to understand how to approach the idea since my approach gives me an illogical answer.
 
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Yes, it does go toward infinity, as you suspected. So what does this mean for another charge as it approaches the one at the origin?
 
Its potential would be stronger the closer this one is to it? And how can a Potential go towards infinity, I feel pretty lost on the subject. Thank you for the help btw!
 
So let's agree that you cannot put zero in the denominator. Physically, the distance between two charges will always be some tiny amount.
If the charge at the origin is positive, bringing another positive charge close to it will become increasingly difficult, as you get closer. Maybe this site will help you. http://hyperphysics.phy-astr.gsu.edu/hbase/electric/potpoi.html
 
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SebastianRM said:
the Potential seems to go towards infinity, which does not make sense,
Indeed it does not. This is the math telling you that ##F=CQ_1Q_2/r^2## for point particles only works when ##r\ne{0}##.

If f you try to bring two charged objects together to drive the potential and the force between them to infinity, some other physics that you've been ignoring for larger values of ##r## will start to matter and Coulomb's law is no longer the whole story. For example, if the objects have non-zero sizes ##R_1## and ##R_2##, you can't reduce the distance between them to less than ##R_1+R_2## so plugging a smaller value into Coulomb's law makes no sense.
 
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