Browse Definitions :
Definition

current

What is Current?

Current is a flow of electrical charge carriers, usually electrons or electron-deficient atoms. The common symbol for current is the uppercase letter I. The standard unit is the ampere, symbolized by A. One ampere of current represents one coulomb of electrical charge (6.24 x 1018 charge carriers) moving past a specific point in one second. Physicists consider current to flow from relatively positive points to relatively negative points; this is called conventional current or Franklin current. Electrons, the most common charge carriers, are negatively charged. They flow from relatively negative points to relatively positive points.

Differences between DC and AC current

Electric current can be either direct or alternating. Direct current (DC) flows in the same direction at all points in time, although the instantaneous magnitude of the current might vary. In an alternating current (AC), the flow of charge carriers reverses direction periodically. The number of complete AC cycles per second is the frequency, which is measured in hertz. An example of pure DC is the current produced by an electrochemical cell. The output of a power-supply rectifier, prior to filtering, is an example of pulsating DC. The output of common utility outlets is AC.

Current density

Current per unit cross-sectional area is known as current density. It is expressed in amperes per square meter, amperes per square centimeter, or amperes per square millimeter. Current density can also be expressed in amperes per circular mil. In general, the greater the current in a conductor, the higher the current density. However, in some situations, current density varies in different parts of an electrical conductor. A classic example is the so-called skin effect, in which current density is high near the outer surface of a conductor, and low near the center. This effect occurs with alternating currents at high frequencies. Another example is the current inside an active electronic component such as a field-effect transistor (FET).

An electric current always produces a magnetic field. The stronger the current, the more intense the magnetic field. A pulsating DC, or an AC, characteristically produces an electromagnetic field. This is the principle by which wireless signal propagation occurs.

Also see voltage, resistance, and Ohm's Law.

This was last updated in October 2021
Networking
  • Network as a Service (NaaS)

    Network as a service, or NaaS, is a business model for delivering enterprise WAN services virtually on a subscription basis.

  • network configuration management (NCM)

    Network configuration management is the process of organizing and maintaining information about all of the components in a ...

  • presentation layer

    The presentation layer resides at Layer 6 of the Open Systems Interconnection (OSI) communications model and ensures that ...

Security
  • backdoor (computing)

    A backdoor attack is a means to access a computer system or encrypted data that bypasses the system's customary security ...

  • Heartbleed

    Heartbleed was a vulnerability in some implementations of OpenSSL, an open source cryptographic library.

  • What is risk management and why is it important?

    Risk management is the process of identifying, assessing and controlling threats to an organization's capital and earnings.

CIO
HRSoftware
  • team collaboration

    Team collaboration is a communication and project management approach that emphasizes teamwork, innovative thinking and equal ...

  • employee self-service (ESS)

    Employee self-service (ESS) is a widely used human resources technology that enables employees to perform many job-related ...

  • learning experience platform (LXP)

    A learning experience platform (LXP) is an AI-driven peer learning experience platform delivered using software as a service (...

Customer Experience
  • headless commerce (headless e-commerce)

    Headless commerce, also called headless e-commerce, is a platform architecture that decouples the front end of an e-commerce ...

  • chief customer officer (CCO)

    A chief customer officer, or customer experience officer, is responsible for customer research, communicating with company ...

  • relationship marketing

    Relationship marketing is a facet of customer relationship management (CRM) that focuses on customer loyalty and long-term ...

Close