Gauss's Law, Sphere (Electric Field

In summary, Gauss's Law is a fundamental law in electromagnetism that relates electric charge and electric fields. It states that the electric flux through a closed surface is equal to the total enclosed charge divided by the permittivity of free space. When applied to a sphere, the electric field is calculated by dividing the enclosed charge by the permittivity of free space multiplied by the surface area of the sphere. The electric field on the surface of a sphere is significant because it is uniformly distributed and perpendicular to the surface, making it easier to calculate at any point. As the distance from the center of a charged sphere increases, the electric field decreases due to its inverse relationship with distance. Gauss's Law can also be used to calculate the electric field
  • #1
jegues
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Homework Statement



See figure attached.

Homework Equations





The Attempt at a Solution



I'm extremely confused.

For r<1,

The total charge enclosed should always be,

[itex] \rho \frac{4}{3\epsilon_{0} \epsilon_{r}} \pi r^{3} = \oint _{S} \vec{E} \cdot \vec{dA} = I[/itex]

The electric field will disperse radially out of the sphere, in the same direction as [itex]\vec{dA}[/itex] so,

[itex]I = E\oint_{S} dA = 4\pi r^{2}E[/itex]

Thus,

[itex]E = \frac{\rho r}{3 \epsilon_{0} \epsilon_{r}}[/itex]

I'm confused about what is suppose to change in the region r > 1 ?

Can someone explain?
 

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  • #2
The charge density is zero for r > 1.
 

Related to Gauss's Law, Sphere (Electric Field

1. What is Gauss's Law?

Gauss's Law is a fundamental law in electromagnetism that describes the relationship between electric charge and electric fields. It states that the electric flux through any closed surface is equal to the total enclosed charge divided by the permittivity of free space.

2. How is Gauss's Law applied to a sphere?

When applying Gauss's Law to a sphere, the electric field is calculated by taking the charge enclosed within the sphere and dividing it by the permittivity of free space multiplied by the surface area of the sphere. This results in a spherically symmetric electric field that decreases as the distance from the center of the sphere increases.

3. What is the significance of the electric field on the surface of a sphere?

The electric field on the surface of a sphere is significant because it is the same at every point on the surface. This means that the electric field lines are uniformly distributed and perpendicular to the surface, making it easier to calculate the electric field at any point on the surface.

4. How does the electric field change as you move away from the center of a charged sphere?

The electric field decreases as you move away from the center of a charged sphere. This is because the electric field is inversely proportional to the square of the distance from the center of the sphere. As the distance increases, the electric field strength decreases.

5. Can Gauss's Law be used to calculate the electric field inside a charged sphere?

Yes, Gauss's Law can be used to calculate the electric field inside a charged sphere. This is because the electric field inside the sphere is also spherically symmetric, and the same principles apply as when calculating the electric field on the surface. However, the charge enclosed within the Gaussian surface must be taken into account when calculating the electric field inside the sphere.

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