Question

What is electric susceptibility in physics?

Answer 1

Electric susceptibility (\(\chi_e\)) is a measure of how easily a material can be polarized by an external electric field. In simple terms, it tells us how much a material will become electrically polarized (how much its charges shift) when an electric field is applied.

When an electric field is applied to a material, the positive and negative charges within the material shift slightly, creating an induced electric dipole moment. Electric susceptibility quantifies this shift. If a material is highly susceptible, it will polarize more easily when exposed to an electric field. If it's not very susceptible, it will polarize less.

Here's a simple way to think about it:

1. High susceptibility: The material is easy to polarize, like a soft material where the charges can move freely.
   

1. Low susceptibility: The material resists polarization, like a hard material where the charges are more fixed in place.
   

The electric susceptibility (\(\chi_e\)) is related to the electric polarization (P) and the electric field (E) by the equation:

\[
P = \epsilon_0 \chi_e E
\]

Where:

1. \(P\) is the polarization (the dipole moment per unit volume),
   

1. \(\epsilon_0\) is the permittivity of free space (a constant),
   

1. \(E\) is the applied electric field.
   

Materials with high electric susceptibility are often called dielectrics. They don't conduct electricity but can store electric charge when exposed to an electric field. Common examples include materials like glass, rubber, or ceramics.