Calculating Electric Flux of a Cube with Charges

In summary, the problem involves a cube with a central charge Q and six charges q placed symmetrically around it. The objective is to determine the electric flux through one of the six planes of the cube. The necessary equations are given, but the distance from the central charge is considered to be irrelevant. The solution involves calculating the flux for each charge and then adjusting for any overlap. There may be an easier way to solve this problem.
  • #1
Ja4Coltrane
225
0

Homework Statement


A cube has a charge Q at its center and has 6 charges q placed symetrically around the central charge. Each one is placed the same distance from the central charge down respective axises which are perpendicular to the planes of the cube which they pass through the center of (does that make sense?) This distance from the central charge is an unnecessary distance. I need to determine the electric flux through one of the six planes.


Homework Equations


Flux=int(E*dA)
Flux=q/(epsilon 0)



The Attempt at a Solution


Well, I'm having a little trouble (I assume my brain just isn't functioning well tonight). I could not see why the distance from the central charge doesn't matter, so I sort of ignored that and assumed that if that is true, it would be fine the put the six charges in contact with the planes.
So I basically added up all of the fluxes. I did Q/(6e) for the middle, q/(2e) for the charge in contact with the surface I care about. I had trouble with the one across from the surface I am fluxing and now realize why my answer for that was wrong. Once I get that one, I can subtract the percents of flux from the one across and the one in contact from 1 and divide that by 4 and multiply that value by q/e and then multiply it by 4.
I know there must be an easier way to do this!
 
Physics news on Phys.org
  • #2
I'm sure I'm missing something simple, but can't figure out what it is. Can anyone help me? Thanks in advance!
 
  • #3



Hello,

First, let's clarify some things about the problem. The distance from the central charge to the six charges does matter, as it affects the electric field at each point. However, for simplicity, we can assume that the distance is the same for all six charges, and that they are all placed at the same distance from the central charge. Also, it is important to note that electric flux is a scalar quantity, so we do not need to worry about direction when calculating it.

To calculate the electric flux through one of the six planes, we can use the equation Flux = ∫E⋅dA, where E is the electric field and dA is the differential area element of the plane. Since the charges are symmetrically placed around the central charge, we can use Gauss's Law to simplify our calculation. Gauss's Law states that the electric flux through a closed surface is equal to the charge enclosed by that surface divided by the permittivity of free space (Flux = Q/ε0).

In this case, we can consider the cube as our closed surface. The charge enclosed by the cube is Q + 6q, since the central charge Q is inside the cube and the six charges q are placed around it. Therefore, the electric flux through one of the planes is given by Flux = (Q + 6q)/ε0.

If we want to calculate the flux through a specific plane, we can divide this value by 6, since there are six planes in total. So, the flux through one of the planes is given by Flux = (Q + 6q)/6ε0.

I hope this helps clarify the problem and provides a simpler solution for you. Let me know if you have any further questions.
 

1. How do you calculate the electric flux of a cube with charges?

The electric flux of a cube with charges can be calculated by taking the dot product of the electric field and the surface area of the cube, and then integrating over the entire surface.

2. What is the formula for electric flux?

The formula for electric flux is Φ=E⋅A, where Φ is the electric flux, E is the electric field, and A is the surface area.

3. How do you determine the direction of electric flux?

The direction of electric flux is determined by the direction of the electric field and the orientation of the surface. The electric flux is positive when the electric field and the normal vector of the surface point in the same direction, and negative when they point in opposite directions.

4. Can the electric flux of a cube with charges be negative?

Yes, the electric flux of a cube with charges can be negative if the electric field and the normal vector of the surface point in opposite directions. This indicates that the electric field is flowing into the surface, rather than out of it.

5. How does the number of charges affect the electric flux of a cube?

The number of charges does not affect the electric flux of a cube, as long as the charges are contained within the cube and the surface of the cube is closed. The electric flux only depends on the electric field and the surface area of the cube.

Similar threads

  • Introductory Physics Homework Help
Replies
6
Views
2K
  • Introductory Physics Homework Help
Replies
6
Views
3K
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
4
Views
1K
  • Introductory Physics Homework Help
Replies
5
Views
6K
  • Introductory Physics Homework Help
Replies
8
Views
1K
  • Introductory Physics Homework Help
Replies
17
Views
6K
  • Introductory Physics Homework Help
Replies
2
Views
993
  • Introductory Physics Homework Help
Replies
3
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
3K
Back
Top