For a good dielectric mediumans.none of theseloss tangent is very largeloss tangent is unityloss tangent is very small Previous Marked for Review Next

The question seems to be asking about the properties of a good dielectric medium. The loss tangent, also known as tan delta, is a measure of a dielectric material's inherent dissipation of electromagnetic energy. It quantifies the inherent lossiness of a system in the absence of any external load or source impedance.

For a good dielectric medium, the loss tangent should be very small. This is because a smaller loss tangent means that the material is less lossy, or in other words, it has less inherent dissipation of electromagnetic energy. This makes it a better insulator, as it can store more energy without losing it as heat.

So, the correct answer is: "loss tangent is very small".