Question

What is called electric susceptibility?

Answer 1

Electric susceptibility is a measure of how much a material can become polarized when an electric field is applied to it. In simple terms, it tells us how easily a material can be influenced by an electric field.

When an electric field is applied to a material, the charges inside the material rearrange themselves. The electric susceptibility quantifies this rearrangement or polarization in relation to the strength of the electric field.

Mathematically, electric susceptibility (denoted as χₑ) is the ratio of the polarization P of the material to the electric field E applied to it:

\[
\chi_e = \frac{P}{\epsilon_0 E}
\]

Where:

1. P is the polarization (the amount of charge displacement in the material).
   

1. E is the electric field applied.
   

1. ε₀ is the permittivity of free space (a constant).
   

Materials can be categorized based on their electric susceptibility:

1. Positive susceptibility: The material becomes polarized in the same direction as the applied electric field. (e.g., most dielectrics)
   

1. Negative susceptibility: The material becomes polarized in the opposite direction of the electric field. (e.g., some metals)
   

1. Zero susceptibility: The material doesn't get polarized in the electric field at all. (e.g., perfect conductors)
   

This property is important in understanding how materials respond to electric fields, which is useful in many areas like capacitors, insulators, and even the design of electronic components.