1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Spherical capacitor

  1. Mar 9, 2014 #1
    1. The problem statement, all variables and given/known data

    A spherical capacitor consists of a spherical conducting shell charge [itex]-Q[/itex] concentric with a smaller conducting sphere of radius [itex]4.0[/itex] cm and charge [itex]Q[/itex]. The larger conducting shell has inner and outer radii of [itex]11.0[/itex] cm and [itex]13.0[/itex] cm, respectively. What is the capacitance of the system in pF?

    2. Relevant equations

    [itex]C = \frac{Q}{\Delta V}[/itex]

    3. The attempt at a solution

    I don't know what to do when the outer shell has a thickness. I know that when it doesn't have a thickness you would do
    [itex] -\int_{r_1}^{r_2} kQ\frac{dr}{r^2} [/itex]
    where [itex]r_1[/itex] and [itex]r_2[/itex] are the inner and outer radii, respectively. But here what do you do for [itex]r_2[/itex]?

    Last edited: Mar 9, 2014
  2. jcsd
  3. Mar 9, 2014 #2
    How would -Q be distributed on the outer shell ?
    Last edited: Mar 9, 2014
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted