Editing Relative permittivity (section)

=== Energy ===
The relative permittivity is an essential piece of information when designing [[capacitor]]s, and in other circumstances where a material might be expected to introduce [[capacitance]] into a circuit. If a material with a high relative permittivity is placed in an [[electric field]],  the magnitude of that field will be measurably reduced within the volume of the dielectric. This fact is commonly used to increase the capacitance of a particular capacitor design. The layers beneath etched conductors in printed circuit boards ([[printed circuit board|PCBs]]) also act as dielectrics.