Part of the Electronics glossary:

Admittance (symbolized Y ) is an expression of the ease with which alternating current ( AC ) flows through a complex circuit or system. Admittance is a vector quantity comprised of two independent scalar phenomena: conductance and susceptance .

Conductance, denoted G , is a measure of the ease with which charge carriers can pass through a component or substance. The more easily the charge carriers move in response to a given applied electric potential, the higher the conductance, which is expressed in positive real-number siemens . Conductance is observed with AC and also with direct current ( DC ).

Susceptance, denoted B , is an expression of the readiness with which an electronic component, circuit, or system releases stored energy as the current and voltage fluctuate. Susceptance is expressed in imaginary number siemens. It is observed for AC, but not for DC. When AC passes through a component that contains susceptance, energy might be stored and released in the form of a magnetic field, in which case the susceptance is inductive (denoted - jB L ), or energy might be stored and released in the form of an electric field, in which case the susceptance is capacitive (denoted + jB C ).

Admittance is the vector sum of conductance and susceptance. Susceptance is conventionally multiplied by the positive square root of -1, the unit imaginary number called symbolized by j , to express Y as a complex quantity G - jB L (when the net susceptance is inductive) or G + jB C (when the net susceptance is capacitive).

In parallel circuits, conductance and susceptance add together independently to yield the composite admittance. In series circuits, conductance and susceptance combine in a more complicated manner. In these situations, it is easier to convert conductance to resistance, susceptance to reactance, and then calculate the composite impedance.

Also see conductance , reactance , resistance , impedance , ohm , siemens , henry , and farad .

This was last updated in March 2011
Posted by: Margaret Rouse

Related Terms

Definitions

  • frequency jammer

    - Frequency jamming is the disruption of radio signals through use of an over-powered signal in the same frequency range. When most people think of frequency jamming, what comes to mind are radio, r... (WhatIs.com)

  • anode

    - An anode is the electrode in a polarized electrical device through which current flows in from an outside circuit. Conversely, a cathode is the eletrode in a polarized electrical device through whi... (WhatIs.com)

  • cathode

    - A cathode is the metallic electrode through which current flows out in a polarized electrical device. Conversely, an anode is the electrode in a polarized electrical device through which current fl... (WhatIs.com)

Glossaries

  • Electronics

    - Terms related to electronics, including definitions about electrical components and words and phrases about computers, laptops parts, digital cameras, televisions and home appliances.

  • Internet applications

    - This WhatIs.com glossary contains terms related to Internet applications, including definitions about Software as a Service (SaaS) delivery models and words and phrases about web sites, e-commerce ...

Ask a Question About admittance (Y)Powered by ITKnowledgeExchange.com

Get answers from your peers on your most technical challenges

Tech TalkComment

Share
Comments

    Results

    Contribute to the conversation

    All fields are required. Comments will appear at the bottom of the article.