How a dielectric polarized?

A dielectric material becomes polarized when an external electric field is applied, causing the positive and negative charges within the material to shift in opposite directions. This displacement of charges results in the formation of electric dipoles, which align with the field. The degree of polarization depends on the strength of the electric field and the material's properties, such as its permittivity. Once the external field is removed, most dielectrics return to their original state, though some materials may retain a degree of polarization, known as ferroelectricity.