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

Click For Summary
SUMMARY

The electrical potential (V) for a point charge at the origin is defined by the equation V = 1/(4πε) * q/r, where r is the distance from the charge. As one approaches the point charge, the potential approaches infinity, indicating that the force between two like charges becomes increasingly difficult to overcome. This phenomenon arises because Coulomb's law, represented by F = CQ1Q2/r², is only valid when r is not equal to zero. When considering the physical sizes of charged objects, the effective distance cannot be reduced below the sum of their radii, making the application of Coulomb's law at very small distances invalid.

PREREQUISITES
  • Understanding of Coulomb's law and its limitations
  • Basic knowledge of electric potential and charge interactions
  • Familiarity with the concept of point charges in electrostatics
  • Awareness of the significance of distance in electric field calculations
NEXT STEPS
  • Explore the implications of electric potential in non-point charge scenarios
  • Study the effects of charge size on electric interactions
  • Learn about the limitations of Coulomb's law in real-world applications
  • Investigate the concept of electric fields and their relationship to potential
USEFUL FOR

Students of physics, electrical engineers, and anyone interested in understanding electrostatics and the behavior of electric charges in proximity.

SebastianRM
Messages
39
Reaction score
4
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.
 
Last edited by a moderator:
Physics news on Phys.org
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
 
  • Like
Likes   Reactions: SebastianRM
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.
 
  • Like
Likes   Reactions: SebastianRM and scottdave

Similar threads

  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 6 ·
Replies
6
Views
1K
  • · Replies 13 ·
Replies
13
Views
3K
  • · Replies 2 ·
Replies
2
Views
1K
Replies
4
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 58 ·
2
Replies
58
Views
5K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K