# I Why is the magnitude of the electric field in a sphere the same?

#### Fontseeker

I was looking at a sphere that has a positive point charge at the center of a sphere with radius R. Now, I understand that the electric field is pointing outwards (in the direction of dA), so

$$d\phi = EdA$$

However, I am told that since the magnitude electrical field is the same because the distance from the charge is the same at each point, this is true:

$$\phi = EA$$

I don't understand how the magnitude of the electrical field is the same in every point of the sphere. For example, wouldn't the magnitude at r= 0.5R be greater than the magnitude at r=R? How can the magnitude be the same?

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Staff Emeritus
In the sphere or on the sphere? dA is what?

"Why is the magnitude of the electric field in a sphere the same?"

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