Register to reply

Electric Field inside and outside of Dielectric sphere

by JayKo
Tags: dielectric, electric, field, inside, sphere
Share this thread:
Mar4-09, 01:54 AM
P: 128
1. The problem statement, all variables and given/known data

A dielectric sphere of radius R has a uniform permanent polarisation P. Determine the electric field both inside and outside the sphere. (Hint: Since div P = 0 everywhere, the electrostatic potential satisfies Laplace's equation. Do not assume that the sphere is characterised by a dielectric constant. Instead, use D = [tex]\epsilon_{0}[/tex]E0 + P.)

2. Relevant equations

use the laplace equation where the general form of potential is:
[tex]V=\Sigma (A_{l}r^{l}P_{l}(cos(theta))+B_{l}*1/(r_{l+1})*P_{l}(cos(theta)))[/tex]

3. The attempt at a solution

set the boundary condition when outside of sphere :
r ->infinity, V->0 hence Al=0

when inside the sphere
r-> 0, V not= infinity hence Bl=0

the next time is to find both the coefficients, a.k.a Al and Bl. so far am i heading the right directions?

my question is also what D = [tex]\epsilon_{0}[/tex]E0 + P purpose here in solving this problem?
Phys.Org News Partner Science news on
Experts defend operational earthquake forecasting, counter critiques
EU urged to convert TV frequencies to mobile broadband
Sierra Nevada freshwater runoff could drop 26 percent by 2100

Register to reply

Related Discussions
Electric field inside a sphere of charge density A/r Introductory Physics Homework 4
Electric Field inside a Sphere (Gauss' Law) Introductory Physics Homework 2
Electric field inside a cavity within a uniformly charged sphere Advanced Physics Homework 1
Find the electric field strength inside a solid sphere. Advanced Physics Homework 8
Electric field inside a charged dielectric Introductory Physics Homework 2