Electric field of line of charge

Click For Summary

Discussion Overview

The discussion revolves around the electric field of a line of charge, specifically addressing whether the electric field at a certain point (point B) along the line of charge is zero or undefined. Participants explore the implications of symmetry and mathematical integration in determining the electric field's value at this point.

Discussion Character

  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • Some participants question whether the electric field at point B, located at the midpoint of a line of charge, is zero or undefined.
  • One participant suggests that the electric field is undefined at the line of charge itself, citing that the electric field is defined in the area surrounding the line of charge.
  • Another participant mentions that taking the integral of 1/x² from 0 to L/2 results in infinity, implying that the electric field is not defined at that point.
  • In contrast, a participant argues that by symmetry, the electric field at the midpoint must be zero because the contributions from both halves of the line of charge cancel each other out.
  • There is a reiteration of the argument that the electric field is defined only in the surrounding area and not on the line itself, reinforcing the notion of it being undefined at the line of charge.

Areas of Agreement / Disagreement

Participants express differing views on whether the electric field at point B is zero or undefined, indicating that multiple competing perspectives remain without a consensus.

Contextual Notes

The discussion includes assumptions about the nature of electric fields and the mathematical treatment of integrals, which may not be fully resolved. The implications of symmetry and the definitions of electric fields in relation to charge distributions are also points of contention.

chessmath
Messages
20
Reaction score
0
Hi
Is electric field zero or undefined?
 

Attachments

  • photo.jpg
    photo.jpg
    36.1 KB · Views: 501
Physics news on Phys.org
chessmath said:
Hi
Is electric field zero or undefined?
At what point? Where along the line of charge is point B?
 
You can clearly see point B is the middle of line of charge with length L. so now question is what is field at this point?
 
chessmath said:
You can clearly see point B is the middle of line of charge with length L.
Too bad you didn't clearly label that point as being exactly in the middle.
so now question is what is field at this point?
What do you think? (Why would you think it would be undefined?)
 
Because electric field is defined in the area around line of charge not on the line of charge.2- when you take integral you get infinity meaning that it is not defined.
 
chessmath said:
when you take integral you get infinity meaning that it is not defined.
Show the integral you are taking.
 
it is the integral of 1/x^2 from 0 to L/2. meaning that putting value of 0 make the integral infinity.
 
chessmath said:
it is the integral of 1/x^2 from 0 to L/2. meaning that putting value of 0 make the integral infinity.
Ah yes, you're right. But by symmetry we know that the field in the middle must be zero--the two halves will cancel out.
 
You are right. But there is second argument that says electrif field is defined in the surronding of line of charge or point charge and not on itself. that's why it is undefined.
 

Similar threads

High School Electric Field Direction: Are We Assuming a Universal Positive Frame?
  • · Replies 20 ·
Replies
20
Views
3K
Undergrad Do Electric field lines propagate by themselves away from a charge?
  • · Replies 73 ·
3
Replies
73
Views
6K
Undergrad Electric Field of Uniformly Charged Infinite Plane
  • · Replies 6 ·
Replies
6
Views
536
Undergrad Electrical breakdown in air in the presence of a single charge
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Does a time varying magnetic field in vacuum produce electric field or not?
  • · Replies 7 ·
Replies
7
Views
2K
High School Seeing both B field lines and E field lines at the same time
  • · Replies 22 ·
Replies
22
Views
2K
Graduate 3D rendering of electric field lines of a swiftly moving charge
  • · Replies 2 ·
Replies
2
Views
1K
High School Thought Experiment on Charge Carriers and Electrical Conduction
  • · Replies 3 ·
Replies
3
Views
980
High School How Does the Electric Field of a Moving Charge Appear?
  • · Replies 29 ·
Replies
29
Views
3K
High School Electric Fields inside Conductors & Gauss' Law
  • · Replies 7 ·
Replies
7
Views
1K