Four Electric Dipoles = What level of electric flux?

In summary, the question asks for the electric flux for a circle with a radius of 1 mm centered at the origin, with electric dipoles located at each "pole". The positive charge of +10 microCoulombs is inside the circle while the negative charge of -10 microCoulombs is just outside the circle. The formula for flux is used to solve this problem, multiplying the + charge by four and dividing by epsilon naught. However, there is some confusion about the orientation of the dipoles and the well-posedness of the question. The diagram provided shows that all the dipoles are in the same plane, with the positive charges on the inside of the circle and the negative charges on the outside. Further
  • #1
mikemartinlfs
8
0

Homework Statement


A circle, centered on the origin, has a radius of 1 mm. At each "pole" (1,0), (0,-1), (-1,0), (0,1) is an electric dipole. The positive charge of +10 microCoulombs is inside the circle, the negative charge of -10 microCoulombs is just outside the circle.

What is the electric flux for the entire circle?

Homework Equations


Flux = q(encl)/e0

The Attempt at a Solution


I think the way to solve this is to simply multiple the + charge by four, as that's the enclosed charge, then divide by epsilon naught. Is this the correct way to go about this? Am I missing something? I thought this would be more difficult than that simple of a solution.
 
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  • #2
Are all these dipoles lying in the same plane as the circle? Assuming that they are, what is the orientation of the dipoles relative to each other and relative to the plane of the circle? I assume that the required flux is through the area of the circle in which case you have to use the definition of flux and not Gauss's law. You need a closed surface to enclose a charge and here there isn't one.

On edit: I have a feeling this is not a well-posed question.
 
  • #3
kuruman said:
Are all these dipoles lying in the same plane as the circle? Assuming that they are, what is the orientation of the dipoles relative to each other and relative to the plane of the circle? I assume that the required flux is through the area of the circle in which case you have to use the definition of flux and not Gauss's law. You need a closed surface to enclose a charge and here there isn't one.

On edit: I have a feeling this is not a well-posed question.

This is a diagram that's like the one given. The space between the + and - charges is 1 mm. They're all in the same plane. Like I mentioned in the OP, the positive four charges are on the inside of the circle with the corresponding - charges on the outside. The question was, what's the flux through the circle.

I hope this helps!

http://imgur.com/a/Whvgi
http://imgur.com/a/Whvgi
 
  • #4
This helps. I thought that "positive" charges meant additional point charges separate from the dipoles. My mistake.

Do you know what the E-field due to a dipole looks like? Draw some electric filed lines and see what you can say about the electric flux, specifically about ## \vec{E} \cdot \hat{n} ## right on the surface of the circle.
 

1. What are electric dipoles?

Electric dipoles are objects or systems that have two equal and opposite electric charges separated by a small distance. This creates a dipole moment, which is a measure of the overall polarity of the object or system.

2. How does electric flux relate to electric dipoles?

Electric flux is a measure of the flow of electric field through a certain area. In the case of electric dipoles, the electric flux is determined by the strength of the dipole moment and the orientation of the dipoles relative to the area being measured.

3. What factors affect the level of electric flux in a system with four electric dipoles?

The level of electric flux in a system with four electric dipoles is affected by the strength of each dipole moment, the distance between the dipoles, and the orientation of the dipoles relative to each other and the area being measured. Additionally, the presence of other charges or electric fields in the system can also impact the level of electric flux.

4. How is the level of electric flux calculated in a system with four electric dipoles?

The level of electric flux can be calculated using the formula Φ = E * A * cosθ, where Φ is the electric flux, E is the strength of the electric field, A is the area being measured, and cosθ is the angle between the electric field and the normal vector of the area. This formula takes into account the effects of the four electric dipoles in the system.

5. Can the level of electric flux ever be negative in a system with four electric dipoles?

Yes, the level of electric flux can be negative in a system with four electric dipoles. This would occur when the dipoles are oriented in such a way that the electric field is directed inward towards the area being measured, resulting in a negative value for the electric flux.

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