Is absolute permittivity and permittivity of free space same?
2 Answers
Absolute permittivity and the permittivity of free space (often denoted as \(\varepsilon_0\)) are related but not the same. Let’s break this down:
### Permittivity of Free Space (\(\varepsilon_0\))
- **Definition**: The permittivity of free space is a physical constant that represents the capability of a vacuum to permit electric field lines. It is a measure of how much electric field (E) is produced per unit charge (Q) in a vacuum.
- **Value**: The value of \(\varepsilon_0\) is approximately \(8.854 \times 10^{-12} \, \text{F/m}\) (farads per meter).
### Absolute Permittivity (\(\varepsilon\))
- **Definition**: Absolute permittivity refers to the permittivity of a specific material, which includes the permittivity of free space along with the material’s response to electric fields (relative permittivity).
- **Relationship**: It is related to the permittivity of free space by the equation:
\[
\varepsilon = \varepsilon_r \cdot \varepsilon_0
\]
where \(\varepsilon_r\) is the relative permittivity (or dielectric constant) of the material. The relative permittivity is a dimensionless number that indicates how much more (or less) the material can store electric field energy compared to vacuum.
### Key Points
- **Vacuum vs. Material**: \(\varepsilon_0\) is specific to vacuum, while absolute permittivity can refer to any medium (like air, water, or a dielectric material).
- **Units**: Both \(\varepsilon_0\) and \(\varepsilon\) are measured in farads per meter (F/m), but their values will differ based on the material in question.
In summary, while absolute permittivity encompasses the permittivity of free space, it also accounts for the effects of the material's properties. Thus, they are not the same but are closely related through the concept of relative permittivity.
### Permittivity of Free Space (\(\varepsilon_0\))
- **Definition**: The permittivity of free space is a physical constant that represents the capability of a vacuum to permit electric field lines. It is a measure of how much electric field (E) is produced per unit charge (Q) in a vacuum.
- **Value**: The value of \(\varepsilon_0\) is approximately \(8.854 \times 10^{-12} \, \text{F/m}\) (farads per meter).
### Absolute Permittivity (\(\varepsilon\))
- **Definition**: Absolute permittivity refers to the permittivity of a specific material, which includes the permittivity of free space along with the material’s response to electric fields (relative permittivity).
- **Relationship**: It is related to the permittivity of free space by the equation:
\[
\varepsilon = \varepsilon_r \cdot \varepsilon_0
\]
where \(\varepsilon_r\) is the relative permittivity (or dielectric constant) of the material. The relative permittivity is a dimensionless number that indicates how much more (or less) the material can store electric field energy compared to vacuum.
### Key Points
- **Vacuum vs. Material**: \(\varepsilon_0\) is specific to vacuum, while absolute permittivity can refer to any medium (like air, water, or a dielectric material).
- **Units**: Both \(\varepsilon_0\) and \(\varepsilon\) are measured in farads per meter (F/m), but their values will differ based on the material in question.
In summary, while absolute permittivity encompasses the permittivity of free space, it also accounts for the effects of the material's properties. Thus, they are not the same but are closely related through the concept of relative permittivity.
No, they aren't the same. Absolute permittivity is the measure of a material's ability to store electrical energy in an electric field, while the permittivity of free space (also known as the vacuum permittivity) is a constant that represents the permittivity of a vacuum. The permittivity of free space is denoted as ε₀ and has a value of approximately \( 8.854 \times 10^{-12} \, \text{F/m} \). Absolute permittivity of a material includes the permittivity of free space multiplied by the material's relative permittivity (dielectric constant).