The ratio \(\frac{\sigma }{{\omega \varepsilon }}\) is called:

1. Intrinsic ratio.

2. Loss tangent.

3. Conduction ratio.

4, Dissipation factor.

Which of the above statements is/are correct?

Loss tangent also known as the dissipation ratio is given by:

\(\tan δ = \frac{σ }{{\omega \varepsilon }}\)

Where ω is the frequency is rad/sec

Loss tangents represent the dissipation of electromagnetic energy of dielectric material.

Derivation:

According to Maxwell's Equation:

\(\vec \nabla \times \vec H = \vec J + \frac{{\partial \vec D}}{{\partial t}}\)

In phasor form, this can be written as:

\(\vec \nabla \times \vec H = \vec J + j\omega D\)

With J̅ = σ E̅ and D̅ = ϵ E̅:

\(\vec \nabla \times \vec H = \sigma \vec E + j\omega\epsilon \vec E\)

The total current is the sum of a real-valued conduction current and an imaginary-valued displacement current. This is drawn as:

The angle δ satisfies:

\(\tan δ = \frac{σ }{{\omega \varepsilon }}\)

This quantity is defined as the loss tangent. 

We observe that the loss tangent is zero for a lossless material, and increases with increasing loss. ∴ The loss tangent provides an alternative way to quantify the effect of loss on the electromagnetic field within a material.