All Questions
6
questions
3
votes
1
answer
376
views
Coulomb force from a variational principle
See the attached discussion from Zangwill's Modern Electrodynamics, and in particular footnote 9. The point of this question is to understand how to recover Coulomb’s force law from an assumed form ...
- 1,095
3
votes
4
answers
282
views
Consistency of existence of point charges and energy in fields
In Feynman lectures, Volume 2 chapter 8 (https://www.feynmanlectures.caltech.edu/II_08.html#Ch1-audio) at the very end Feynman remarks
We must conclude that the idea of locating the energy in the ...
12
votes
8
answers
3k
views
Why is the electrostatic force felt in straight lines?
When two positive charges are kept close, they get repelled in the direction of a line joining both the charges. Why is it so?
Also, why is the repulsion in a straight path?
In both the cases, the ...
- 662
5
votes
2
answers
1k
views
Why does field strength follow the inverse square law but potential does not?
Either in a gravitational or electrical field, let's say an electrical field, the electrical field strength follows the inverse square law. This is fairly intuitive just due to the geometry of the ...
- 109
0
votes
1
answer
133
views
Quantifying potential energy
As per the definition of potential energy we kept a fixed charge, and in the presence of an electric field of the fixed charge, we release another charge of the same sign moving towards the fixed ...
- 529
0
votes
1
answer
678
views
What is the electric potential at the point charge, at the source of field?
$$V(r)=k_eq/r$$
What is the electric potential when the test charge is placed very very close to the source charge, ie when $r=0$? Is it infinity?
- 295