Can Point Charges Be Used to Approximate Charged Bodies?

In summary, when the sizes of charged bodies are significantly smaller than the distances between them, they can be treated as point charges. This is because the differences in electric field between a charged cube and a charged tetrahedron are negligible at a far enough distance, making the use of point charges a more convenient and less complicated approach. The exact definition of "size" is not specified in this approximation, but it is generally considered to be the largest distance across the object. To see significant differences, one must be at a much further distance from the object.
  • #1
sahilmm15
100
27
"If the sizes of charged bodies are very small as compared to the distances between them, we treat them as point charges". Can you explain me the statement. And what does "sizes of charged bodies" refer here. Thanks
 
Physics news on Phys.org
  • #2
The electric field of a charged cube, for example, is different from a charged tetrahedron. Very far from the object, though, the differences are negligible, and the difference from the field of a point charge is negligible. So we can just treat it as a point charge and save ourselves from some nasty integrals.

The size of the body, in this context, isn't really precisely defined, since we're talking about an approximation. It's something like the largest distance there is across the object. You need to be much further away than that.
 
  • #3
Ibix said:
The electric field of a charged cube, for example, is different from a charged tetrahedron. Very far from the object, though, the differences are negligible, and the difference from the field of a point charge is negligible. So we can just treat it as a point charge and save ourselves from some nasty integrals.

The size of the body, in this context, isn't really precisely defined, since we're talking about an approximation. It's something like the largest distance there is across the object. You need to be much further away than that.
Thanks for the reply. I appreciate it.
 
  • Like
Likes Ibix

1. Can point charges accurately represent the behavior of a charged body?

No, point charges are a simplified model used in physics to approximate the behavior of a charged body. They do not accurately represent the distribution of charge or the complex interactions between charges within a body.

2. How are point charges used to approximate charged bodies?

Point charges are used to represent the overall charge of a body, with each point charge representing a small portion of the total charge. The forces and interactions between these point charges are then calculated to approximate the behavior of the charged body.

3. What are the limitations of using point charges to approximate charged bodies?

Point charges are limited in their ability to accurately represent the shape, size, and distribution of charge within a body. They also do not account for the effects of external fields or the movement of charges within the body.

4. Can point charges be used to approximate all types of charged bodies?

No, point charges are most commonly used to approximate simple, symmetrical charged bodies. They are not as accurate for complex or irregularly shaped bodies.

5. Are there any alternative methods for approximating charged bodies?

Yes, there are other methods such as finite element analysis or boundary element method that can be used to more accurately approximate charged bodies. These methods take into account the shape, size, and distribution of charge within a body.

Similar threads

Replies
4
Views
731
Replies
36
Views
3K
Replies
24
Views
1K
Replies
11
Views
866
  • Electromagnetism
Replies
18
Views
914
Replies
1
Views
1K
  • Electromagnetism
2
Replies
36
Views
3K
Replies
9
Views
950
Replies
9
Views
1K
Replies
73
Views
3K
Back
Top