Dielectric losses may occur due to:

Question

Question

This question was previously asked in

AAI (ATC) Junior Executive Official Paper (Held On: 30 Nov 2018 Shift 2)

Answer 1

Dielectric losses occur due to Polarisation

One of the important properties of the dielectric material is its permittivity. Permittivity ϵ is the measure of the ability of a material to be polarized by an electric field.
ϵ is complex and is frequency dependent. The imaginary part corresponds to a phase shift of polarization relative to “E” and leads to the attenuation of Electromagnetic waves passing through the medium.

When a dielectric is subjected to an alternating electric field then, the dielectric loss will be:

\(W\left( t \right)=\frac{1}{2}W{{\epsilon }_{0}}{{\epsilon }_{\text{r}}}~E_{0}^{2}~W/{{m}^{3}}\)

ω = Angular frequency

ϵ0 = Absolute permittivity

ϵr“ = Imaginary part of complex relative permittivily

E0 = Peak Voltage.