permittivity
Definition
Noun: A physical property of a material that measures its ability to store electrical energy in an electric field. It is the ratio of the electric displacement field to the electric field intensity, often denoted by the Greek letter ε (epsilon). In vacuum, it is a constant called the permittivity of free space (ε₀).
Usage Examples
- (The material's ability to resist an electric field and store energy.)
- (The property that affects capacitance.)
- (The material's ability to polarize in an electric field.)
Advanced Usage
- Relative permittivity: The ratio of a material's permittivity to the permittivity of free space (εᵣ = ε/ε₀).
- The relative permittivity of air is approximately 1.0006. (A dimensionless value indicating how much more a material can store energy than vacuum.)
- Complex permittivity: A measure that accounts for both energy storage and energy loss in a material, often used in alternating current (AC) fields.
- At high frequencies, the complex permittivity of a polymer affects its microwave absorption. (A frequency-dependent property with real and imaginary parts.)
Variants and Related Words
- Permittivity of free space (n): The absolute permittivity of a vacuum, approximately 8.854 × 10⁻¹² F/m.
- The permittivity of free space is a fundamental constant in electromagnetism. (The baseline value for all other permittivity measurements.)
- Permittivity tensor (n): A matrix representation of permittivity in anisotropic materials.
- Crystals often require a permittivity tensor to describe their electrical response. (A directional property in non-uniform materials.)
Synonyms
- Dielectric constant: A common synonym for relative permittivity, though technically less precise.
- The dielectric constant of glass is around 5 to 10. (A measure of its insulating ability.)
- Electric permittivity: A more formal term emphasizing the electrical nature of the property.
- Electric permittivity is crucial in designing microwave circuits. (The property used in electromagnetic theory.)
Related Idioms
- (No common idioms exist for this technical term.)