Spherical capacitor problem help

6 replies · 3K views · last reply
mopar969
Messages
200
Reaction score
0
I need help on starting and solving this problem. See attachment for problem.
 
Attachments
  • Typed homework problem 2 on spherical capacitor: solid conductor radius 0.5 mm with charge 7.4 microCoulombs, dielectric er = 1.8 out to 1.2 mm, outer shell radius 2.0 mm with charge density rho = 5r; find electric field everywhere.
    3.jpg
    33.8 KB · Views: 480
mopar969 said:
yes.

In that case, use Gauss' law to attempt this problem, and post your attempt here. We can't just give you the answers without some effort on your part towards a solution.
 
I know that gauss law says q over epsilon zero but how do I incorporate this for the dielectric material?
 
I know that the electric field for a dielectric is e = Q all over 4 pi k epsilon zero r^2. I also know that the electric field for the innerest conductor can be found using E = 1 over 4 pi epsilon zero time Q over r^2. Using this equation I got 3.25 x 10 ^ -9. However I do not know how to solve the outer most shell given with the charge per volume value. And for my dielectric electric field formula how do I get the er value of 1.8 that was given in the problem into the equation?