Browse Definitions :
Definition

volt

The volt (symbolized V) is the Standard International (SI) unit of electric potential or electromotive force. A potential of one volt appears across a resistance of one ohm when a current of one ampere flows through that resistance. Reduced to SI base units, 1 V = 1 kg times m2 times s-3 times A-1 (kilogram meter squared per second cubed per ampere).

Voltage can be expressed as an average value over a given time interval, as an instantaneous value at a specific moment in time, or as an effective or root-mean-square (rms) value. Average and instantaneous voltages are assigned a polarity either negative (-) or positive (+) with respect to a zero, or ground, reference potential. The rms voltage is a dimensionless quantity, always represented by a non-negative real number.

For a steady source of direct-current (DC) electric potential, such as that from a zinc-carbon or alkaline electrochemical cell, the average and instantaneous voltages are both approximately +1.5 V if the negative terminal is considered the common ground; the rms voltage is 1.5 V. For standard utility alternating current (AC), the average voltage is zero (the polarity constantly reverses); the instantaneous voltage ranges between approximately -165 V and +165 V; the rms voltage is nominally 117 V.

Voltages are sometimes expressed in units representing power-of-10 multiples or fractions of one volt. A kilovolt (symbolized kV) is equal to one thousand volts (1 kV = 103 V). A megavolt (symbolized MV) is equal to one million volts (1 MV = 106 V). A millivolt (symbolized mV) is equal to one-thousandth of a volt (1 mV = 10-3 V). A microvolt (symbolized µV) is equal to one-millionth of a volt (1 µV = 10-6 V).

Also see Ohm's Law, prefix multipliers, Standard International (SI) system of units, and voltage.

This was last updated in September 2005

Join the conversation

1 comment

Send me notifications when other members comment.

Please create a username to comment.

It is a nice definition but I would like a smaller version so I can read it quickly.
Cancel

-ADS BY GOOGLE

File Extensions and File Formats

Powered by:

SearchCompliance

  • Whistleblower Protection Act

    The Whistleblower Protection Act of 1989 is a law that protects federal government employees in the United States from ...

  • smart contract

    A smart contract, also known as a cryptocontract, is a computer program that directly controls the transfer of digital currencies...

  • risk map (risk heat map)

    A risk map, also known as a risk heat map, is a data visualization tool for communicating specific risks an organization faces. A...

SearchSecurity

  • certificate authority (CA)

    A certificate authority (CA) is a trusted entity that issues digital certificates, which are data files used to cryptographically...

  • hacktivism

    Hacktivism is the act of hacking, or breaking into a computer system, for a politically or socially motivated purpose.

  • advanced persistent threat (APT)

    An advanced persistent threat (APT) is a prolonged and targeted cyberattack in which an intruder gains access to a network and ...

SearchHealthIT

  • Cerner Corp.

    Cerner Corp. is a public company in North Kansas City, Mo., that provides various health information technologies, ranging from ...

  • clinical decision support system (CDSS)

    A clinical decision support system (CDSS) is an application that analyzes data to help healthcare providers make decisions and ...

  • Health IT (health information technology)

    Health IT (health information technology) is the area of IT involving the design, development, creation, use and maintenance of ...

SearchDisasterRecovery

  • tabletop exercise (TTX)

    A tabletop exercise (TTX) is a disaster preparedness activity that takes participants through the process of dealing with a ...

  • risk mitigation

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

  • ransomware recovery

    Ransomware recovery is the process of resuming options following a cyberattack that demands payment in exchange for unlocking ...

SearchStorage

  • SSD (solid-state drive)

    An SSD (solid-state drive) is a type of nonvolatile storage media that stores persistent data on solid-state flash memory.

  • file system

    In a computer, a file system -- sometimes written filesystem -- is the way in which files are named and where they are placed ...

  • storage virtualization

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

Close