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

Click For Summary
SUMMARY

The discussion centers on the uniformity of the electric field magnitude around a sphere with a positive point charge at its center. It is established that the electric field (E) is constant at all points on the surface of the sphere due to the symmetry of the charge distribution. The relationship between electric flux (φ), electric field (E), and area (A) is defined by the equation φ = EA, confirming that the electric field remains the same at every point on the sphere's surface, regardless of the radius (R). This uniformity arises from the inverse square law of electrostatics, which dictates that the electric field strength decreases with distance from the charge, but remains constant on the surface of a spherical shell.

PREREQUISITES
  • Understanding of electrostatics and electric fields
  • Familiarity with Gauss's Law
  • Knowledge of spherical symmetry in physics
  • Basic mathematical skills for manipulating equations
NEXT STEPS
  • Study Gauss's Law and its applications in electrostatics
  • Explore the concept of electric field lines and their properties
  • Learn about the inverse square law in relation to point charges
  • Investigate the effects of charge distribution on electric fields
USEFUL FOR

Students of physics, educators teaching electrostatics, and anyone interested in understanding electric fields and their behavior in spherical geometries.

Fontseeker
Messages
30
Reaction score
4
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?
 
Physics news on Phys.org
In the sphere or on the sphere? dA is what?
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 11 ·
Replies
11
Views
4K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 5 ·
Replies
5
Views
2K
  • · Replies 4 ·
Replies
4
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K
  • · Replies 73 ·
3
Replies
73
Views
6K