- #1

manofphysics

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I just have a small question regarding lorentz cavity:

Refer to a small lorentz cavity in a uniformly polarised dielectric. as shown in fig.

[tex]E_{ex}[/tex]: External electric field.

[tex]E_{P}[/tex]: Electric field in the uniformly polarised dielectric (when sphere has NOT been cut out)

[tex]E_{L}[/tex]:Electric field due to surface charge on cavity

[tex]E_{near}[/tex]:Field due to dipoles inside cavity.

Now, [tex]E=E_{ex}+E_{P}+E_{L}+E_{near}[/tex]

But, does not [tex]E_{P}[/tex] change if we cut out a sphere from the polarised dielectric?

Is it that we are neglecting the small change in [tex]E_{P}[/tex] due to cut out sphere and our result is an useful approximation, but not exact?

Please, any help will be appreciated. I need to understand this for my term exam.

Refer to a small lorentz cavity in a uniformly polarised dielectric. as shown in fig.

[tex]E_{ex}[/tex]: External electric field.

[tex]E_{P}[/tex]: Electric field in the uniformly polarised dielectric (when sphere has NOT been cut out)

[tex]E_{L}[/tex]:Electric field due to surface charge on cavity

[tex]E_{near}[/tex]:Field due to dipoles inside cavity.

Now, [tex]E=E_{ex}+E_{P}+E_{L}+E_{near}[/tex]

But, does not [tex]E_{P}[/tex] change if we cut out a sphere from the polarised dielectric?

Is it that we are neglecting the small change in [tex]E_{P}[/tex] due to cut out sphere and our result is an useful approximation, but not exact?

Please, any help will be appreciated. I need to understand this for my term exam.