permittivity

(noun)

A property of a dielectric medium that determines the forces that electric charges placed in the medium exert on each other.

Related Terms

Examples of permittivity in the following topics:

  • Capacitors with Dielectrics

    • If it has a high permittivity, it also increases the capacitance for any given voltage.
    • where ε is the permittivity, A is the area of the capacitor plates (assuming both are the same size and shape), and d is the thickness of the dielectric.

  • Parallel-Plate Capacitor

    • For a parallel-plate capacitor, capacitance (C) is related to dielectric permittivity (ε), surface area (A), and separation between the plates (d):
    • Voltage (V) of a capacitor is related to distance between the plates, dielectric permittivity, conductor surface area, and charge (Q) on the plates:

  • Capacitance

    • Ultimately, in such a capacitor, q depends on the surface area (A) of the conductor plates, while V depends on the distance (d) between the plates and the permittivity (εr) of the dielectric between them.

  • Parallel-Plate Capacitor

    • Accordingly, capacitance is greatest in devices with high permittivity, large plate area, and minimal separation between the plates.

  • Solving Problems with Vectors and Coulomb's Law

    • In this equation, k is equal to $\frac{1}{4\pi\varepsilon_0\varepsilon }$,where $\varepsilon_0$ is the permittivity of free space and $\varepsilon$ is the relative permittivity of the material in which the charges are immersed.

  • Maxwell's Equations

    • The field (E) points towards negative charges and away from positive charges, and from the microscopic perspective, is related to charge density (ρ) and vaccuum permittivity (ε0, or permittivity of free space) as:

  • Electric Field and Changing Electric Potential

    • where ε0 is the electric constant, otherwise known as permittivity of free space.

  • Lattice Energy

    • In this equation, NA is Avogadro's constant; M is the Madelung constant, which depends on the crystal geometry; z+ is the charge number of the cation; z- is the charge number of the anion; e is the elementary charge of the electron; n is the Born exponent, a characteristic of the compressibility of the solid; $\epsilon _o$ is the permittivity of free space; and r0 is the distance to the closest ion.

  • Superposition of Forces

    • where r is the separation distance and ε0 is electric permittivity.

  • Description of the Hydrogen Atom

    • where me is the mass of the electron, qe is the charge of the electron, h is the Planck constant, and ε0 is the vacuum permittivity.