Browse Definitions :
Definition

permittivity (electric permittivity)

Permittivity, also called electric permittivity, is a constant of proportionality that exists between electric displacement and electric field intensity. This constant is equal to approximately 8.85 x 10-12 farad per meter (F/m) in free space (a vacuum). In other materials it can be much different, often substantially greater than the free-space value, which is symbolized eo.

In engineering applications, permittivity is often expressed in relative, rather than in absolute, terms. If eo represents the permittivity of free space (that is, 8.85 x 10-12 F/m) and e represents the permittivity of the substance in question (also specified in farads per meter), then the relative permittivity, also called the dielectric constant er, is given by:

er = e / eo
= e (1.13 x 1011)

Various substances have dielectric constants er greater than 1. These substances are generally called dielectric materials, or simply dielectrics. Commonly used dielectrics include glass, paper, mica, various ceramics, polyethylene, and certain metal oxides. Dielectrics are used in capacitors and transmission lines in alternating current (AC), audio frequency (AF), and radio frequency (RF) applications.

Also see farad per meter, capacitor, and electric field.

This was last updated in September 2005
SearchCompliance
  • OPSEC (operations security)

    OPSEC (operations security) is a security and risk management process and strategy that classifies information, then determines ...

  • smart contract

    A smart contract is a decentralized application that executes business logic in response to events.

  • compliance risk

    Compliance risk is an organization's potential exposure to legal penalties, financial forfeiture and material loss, resulting ...

SearchSecurity
  • threat modeling

    Threat modeling is a procedure for optimizing application, system or business process security by identifying objectives and ...

  • distributed denial-of-service (DDoS) attack

    A distributed denial-of-service (DDoS) attack is one in which multiple compromised computer systems attack a target, such as a ...

  • social engineering

    Social engineering is an attack vector that relies heavily on human interaction and often involves manipulating people into ...

SearchHealthIT
SearchDisasterRecovery
  • change control

    Change control is a systematic approach to managing all changes made to a product or system.

  • disaster recovery (DR)

    Disaster recovery (DR) is an organization's ability to respond to and recover from an event that affects business operations.

  • risk mitigation

    Risk mitigation is a strategy to prepare for and lessen the effects of threats faced by a business.

SearchStorage
  • bare-metal cloud

    Bare-metal cloud is a public cloud service that offers dedicated hardware resources without any installed operating systems or ...

  • race condition

    A race condition is an undesirable situation that occurs when a device or system attempts to perform two or more operations at ...

  • storage security

    Storage security is the group of parameters and settings that make storage resources available to authorized users and trusted ...

Close