Dielectric

Key Stage 5

A dielectric is a material that increases the capacity of a parallel-plate capacitor to store charge when placed between the plates.

Dielectrics increase the capacitance of a capacitor by reducing the electric field between the plates.
Common dielectrics include polythene, waxed paper, and ceramics.
The ability of a dielectric to increase capacitance is measured by its relative permittivity or dielectric constant.
Dielectrics are used to prevent electrical breakdown and improve energy storage in capacitors.
Dielectrics also influence the electric field distribution and energy storage in the capacitor.

Polythene used as a dielectric in high-voltage capacitors.
Ceramic dielectrics in multilayer ceramic capacitors (MLCCs) for electronic circuits.