- #1
Domfunkle
- 9
- 0
Homework Statement
A hollow spherical shell carries charge density [tex]\rho[/tex] = [tex]\frac{k}{r^{2}}[/tex]
in the region a [tex]\leq[/tex] r [tex]\leq[/tex] b. Find the electric field in the three regions:
i. r < a
ii. a < r < b
iii. r > b
Homework Equations
Surface Area of a sphere
Coulombs Law
Gauss's Law
The Attempt at a Solution
i. This is easy, centre of a hollow charged sphere has E = 0
ii. ?
iii. Just used the sphere as a point charge and using the surface area of the sphere's outer radius, multiplied by the charge density to get the charge, and then just used Coulomb's Law to get E.
My problem is with part ii. The Electric Field within the thickness of the sphere. The question never specified that it was an insulator or a conductor, so I'm just going to assume that the majority of the charge lies on the outer radius surface, and that the inner radius surface should have little-to-no charge to account for the 0 E in the hollow centre, and the Field increases as the radius increases in the thickness: E [tex]\propto[/tex] r
Would i be right in this assumption? How might I describe this mathematically?