Explain the significance of the loss tangent of a dielectric material.

The loss tangent contains a very small value for free space. For solid materials there tan δ = 0.003, that is equivalent to a Q that is quality factor of 3000. A quite good value of Q for a coil is approximately 300. That is why more significance to losses in a coil is specified. The variation of tan δ with frequency will demonstrate normal resonance behaviour. It is shown in the figure below. The curves of tan δ contain the largest value in the region of frequencies here is a sharp change in the dielectric constant. In case of ionic resonance it change in the dielectric constant arises from microwave to infrared areas of frequencies. The dielectric losses related with ionic vibrations are generally referred to as infrared absorption. Likewise the losses in the optical region related with electronic vibrations are referred to as optical absorption. Therefore it is possible to predict whether the dielectric properties are because of ionic or electronic polarisation.