Interior of an insulating sphere

Storyboard

In the case of an insulating sphere with a homogeneous charge distribution, the charges cannot move. The electric field can be calculated by assuming spherical symmetry and defining the Gaussian surface as a sphere with a given radius. In this way, the electric field and potential will depend on the charge enclosed by this surface.

>Model

ID:(2077, 'ky')


Internal electric field of a charged sphere

Description

Since Gauss's law states that the total flow of electric field through a closed surface is proportional to the enclosed charge, using 11377:

equation=11377

can be applied to the case of a single surface Surface ($S$) corresponding to a sphere of radius Radius ($r$):

equation=4665

In this case, the amount of Charge ($Q$) enclosed by the Gaussian surface corresponds only to the fraction of the total volume contained within the radius Radius ($r$). As the charge distribution is homogeneous, the enclosed charge is proportional to the interior volume of the Gaussian sphere:

$q_s=\displaystyle\frac{Q}{R^3}r^3$

With this you finally obtain:

equation

ID:(11376, 'gm')


Volumetric Load Density

Description

When Charge ($Q$) is distributed over a Volume ($V$), a Volume charge density ($\rho_e$) can be defined that represents the amount of charge contained per unit volume:



From this volumetric load distribution it is defined:

$\rho_e = \displaystyle\frac{ Q }{ V }$

$V$
Volume
$m^3$
$Q$
Charge
$C$
$\rho_e$
Volume charge density
$C/m^3$

ID:(15784, 'gm')


Interior of an insulating sphere

Description

Calculations


First, select the equation:   to ,  then, select the variable:   to 

Symbol
Equation
Solved
Translated

Calculations

Symbol
Equation
Solved
Translated

 Variable   Given   Calculate   Target :   Equation   To be used



Variables

Symbol
Text
Variable
Value
Units
Calculate
MKS Value
MKS Units
$r$
r
Radius
m
$R$
R
Sphere radius
m
$V$
V
Volume
m^3
$\epsilon$
epsilon
Dielectric constant
-
$Q$
Q
Charge
C
$E_i$
E_i
Electric field, sphere, interior
V/m
$\epsilon_0$
epsilon_0
Electric field constant
C^2/m^2N
$\rho_e$
rho_e
Volume charge density
C/m^3

ID:(2077, 0)


gphysics.net - Dr. Willy H. Gerber
Palos Verdes, Costa de Corral, Chile