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**Complex Dielectric Permittivity!!!**

## Homework Statement

Calculate the power dissipated per unit cycle in a dielectric medium per unit volume in terms of the dielectric loss and the strength of the electric field

The previous question was:

Why does the dielectric permittivity of a material in general become complex for an alternating signal applied across it. Whats is the significance of the real part of the dielectric permittivity?

## Homework Equations

Obvious ones:

[tex]W=\frac{1}{2}CV^2[/tex]

[tex]C=\frac{k\epsilon_{0}A}{d}[/tex]

Found this on wikipedia:

[tex]\hat{\epsilon}(\omega)=\epsilon'(\omega)-i\epsilon''(\omega)[/tex]

## The Attempt at a Solution

[tex]W=\frac{1}{2}(\frac{k\epsilon_{0}A}{d})V^2[/tex]

Im guessing the complex part of [tex]\hat{\epsilon}(\omega)[/tex] accounts 4 the lost power so i put that in for [tex]k\epsilon_{0}[/tex]

Divided by dA to change it to per unit volume and divided by [tex]\frac{\omega}{2\pi}[/tex] to get it for one cycle. (Im presuming by cycle they mean period of the AC current)

Which gives:

[tex]-\frac{\pi\epsilon''(\omega)V^2}{d^2\omega}[/tex]

I dont no what dielectric loss is and i doubt im allowed to just put in [tex]\epsilon''(\omega)[/tex]

Ne1 no anything about dielectric permittivity?

Ne1 wanna take a ramdom guess like i just did

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