Browse Definitions :
Definition

siemens (mho)

(Siemens AG is a German company engaged in electrical engineering and electronics.)

The siemens (symbolized S) is the Standard International (SI) unit of electrical conductance. The archaic term for this unit is the mho (ohm spelled backwards). Siemens are also used, when multiplied by imaginary numbers, to denote susceptance in alternating current (AC) and radio frequency (RF) applications. Reduced to base SI units, 1 S is the equivalent of one second cubed ampere squared per kilogram per meter squared (1 s3 · A2 · kg-1 · m-2). The siemens is also the equivalent of an ampere per volt (A/V).

In a direct current (DC) circuit, a component has a conductance of 1 S when a potential difference of one volt (1 V) produces a current of one ampere (1 A) through the component. Thus, one siemens is the equivalent of one ohm. But mathematically, resistance and conductance are reciprocals of each other. If R is the resistance of a component in ohms and G is the conductance in siemens,

R = 1 / G

and

G = 1 / R

In AC and RF circuits, conductive siemens behave the same as they do in DC circuits, provided the root-mean-square (rms) AC voltage is specified. In AC and RF circuits, susceptance exists only when there is a net capacitance or inductance. Capacitive susceptances have positive imaginary number values; inductive susceptances have negative imaginary-number values. The susceptance of a particular capacitor or inductor depends on the frequency.

Conductances and susceptances are sometimes expressed in units representing power-of-10 multiples or fractions of 1 S. A kilosiemens (1 kS) is equal to one thousand (103) siemens. A megasiemens (1 MS) is equal to one million (106) siemens. A millisiemens (1 mS) is equal to one-thousandth (10-3) of a siemens. A microsiemens (1 uS) is equal to one-millionth (10-6) of a siemens.

Also see conductance, Ohm's Law, prefix multipliers, resistance, reactance, ohm, and Standard International (SI) system of units.

This was last updated in February 2008

Continue Reading About siemens (mho)

SearchCompliance

  • information governance

    Information governance is a holistic approach to managing corporate information by implementing processes, roles, controls and ...

  • enterprise document management (EDM)

    Enterprise document management (EDM) is a strategy for overseeing an organization's paper and electronic documents so they can be...

  • risk assessment

    Risk assessment is the identification of hazards that could negatively impact an organization's ability to conduct business.

SearchSecurity

  • honeypot (computing)

    A honeypot is a network-attached system set up as a decoy to lure cyber attackers and detect, deflect and study hacking attempts ...

  • spam trap

    A spam trap is an email address that is used to identify and monitor spam email.

  • cracker

    A cracker is someone who breaks into someone else's computer system, often on a network; bypasses passwords or licenses in ...

SearchHealthIT

SearchDisasterRecovery

  • risk mitigation

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

  • call tree

    A call tree is a layered hierarchical communication model that is used to notify specific individuals of an event and coordinate ...

  • Disaster Recovery as a Service (DRaaS)

    Disaster recovery as a service (DRaaS) is the replication and hosting of physical or virtual servers by a third party to provide ...

SearchStorage

  • cloud testing

    Cloud testing is the process of using the cloud computing resources of a third-party service provider to test software ...

  • storage virtualization

    Storage virtualization is the pooling of physical storage from multiple storage devices into what appears to be a single storage ...

  • erasure coding

    Erasure coding (EC) is a method of data protection in which data is broken into fragments, expanded and encoded with redundant ...

Close