DIELECTRIC ABSORPTION Meaning and
Definition
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Dielectric absorption refers to a property exhibited by certain materials, particularly dielectrics, which allows them to store electric charge temporarily. When a dielectric material is subjected to an electric field or voltage, its molecules become polarized, aligning themselves with the field. This polarization enables the material to store energy in the form of electric charge, even after the electric field is removed.
The phenomenon of dielectric absorption arises due to the relaxation time of the material's molecules. As the electric field is removed, the polarization of the molecules gradually decreases, but not instantaneously. Some of the polarized molecules take time to reorient or relax back to their original state. This delayed relaxation process leads to the continued release of stored charge, resulting in a phenomenon known as dielectric absorption or dielectric relaxation.
Dielectric absorption is often measured using a parameter known as the dielectric absorption ratio (DAR). This ratio is the ratio of the resistance that accumulates after a dielectric material has been charged for a certain period to the resistance initially accumulated. A high DAR indicates that the dielectric material exhibits significant dielectric absorption.
Applications of dielectric absorption can be found in various fields, including capacitors, electrical insulation, energy storage systems, and electronic devices. Understanding and controlling dielectric absorption is crucial for optimizing the performance and efficiency of these systems.
Etymology of DIELECTRIC ABSORPTION
The term "dielectric absorption" is derived from the combination of two words:
1. Dielectric: The word "dielectric" comes from the Greek words "dia" (meaning through) and "electric" (related to electricity). It refers to a substance or material that does not conduct electric current easily but can store electric charge or energy temporarily. Dielectrics are commonly used in capacitors and insulators.
2. Absorption: The word "absorption" originates from the Latin word "absorptio" (meaning a swallowing up). It refers to the process of taking in or assimilating something, typically a substance or energy, into another substance.
Therefore, "dielectric absorption" describes the phenomenon where a dielectric material absorbs and temporarily retains some of the electrical energy (in the form of charge) it is exposed to, rather than immediately releasing or dissipating it.
