Question

What is the difference between dielectric and susceptibility?

Answer 1

In simple terms, dielectric and susceptibility are concepts related to the behavior of materials in an electric field, but they refer to different things.

Dielectric:

A dielectric is a material that does not conduct electricity but can support an electric field. These materials are insulators, like glass, rubber, or plastic. When a dielectric material is placed in an electric field, it gets polarized, meaning its positive and negative charges are displaced slightly, but it doesn't allow current to flow. Dielectrics are commonly used in capacitors and electrical insulations because they can store electrical energy when subjected to an electric field.

Susceptibility:

Electric susceptibility is a measure of how easily a material becomes polarized in response to an electric field. It tells us how much the material will become polarized when an external electric field is applied. The higher the susceptibility, the more easily the material can be polarized.

1. Mathematically, susceptibility (χ) is related to the polarization \( P \) of the material and the applied electric field \( E \) by the formula:
   

  \[
  P = \chi \cdot \epsilon_0 \cdot E
  \]
  where:
  - \( P \) is the polarization of the material,
  - \( \epsilon_0 \) is the permittivity of free space,
  - \( E \) is the applied electric field,
  - \( \chi \) is the electric susceptibility.

Key Differences:

1. Nature:
   

   - Dielectric refers to the type of material, which is a non-conductor of electricity but can be polarized in an electric field.
   - Susceptibility is a property of a material that measures how much it gets polarized when exposed to an electric field.

1. Purpose:
   

   - Dielectric materials are used for insulating purposes in electrical devices like capacitors.
   - Susceptibility tells us about the material's response to an electric field and how easily it can be polarized.

1. Relationship:
   

   - The dielectric constant (or permittivity) of a material is related to its susceptibility. The greater the susceptibility, the higher the dielectric constant.

To summarize:

1. Dielectric = Material type (non-conductive, can be polarized).
   

1. Susceptibility = A measure of how easily a material becomes polarized in an electric field.