Electricity

Mains electricity is the general-purpose alternating-current (AC) electric power supply.

Static electricity is an imbalance of electric charges within or on the surface of a material.

Alternating current (AC), is an electric current in which the flow of electric charge periodically reverses direction, whereas in direct current (DC, also dc), the flow of electric charge is only in one direction.

An electric battery is a device consisting of one or more electrochemical cells with external connections provided to power electrical devices such as flashlights, smartphones, and electric cars.

A capacitor (originally known as a condenser) is a passive two-terminal electrical component used to temporarily store electrical energy in an electric field.

Direct current (DC) is the unidirectional flow of electric charge.

An electrical network is an interconnection of electrical components (e.g. batteries, resistors, inductors, capacitors, switches) or a model of such an interconnection, consisting of electrical elements (e.g. voltage sources, current sources, resistances, inductances, capacitances).

An electric potential (also called the electric field potential or the electrostatic potential) is the amount of electric potential energy that a unitary point electric charge would have if located at any point in space, and is equal to the work done by an external agent in carrying a unit of positive charge from the arbitrarily chosen reference point (usually infinity) to that point without any acceleration.

Electrical resistivity (also known as resistivity, specific electrical resistance, or volume resistivity) is an intrinsic property that quantifies how strongly a given material opposes the flow of electric current.

The electrical resistance of an electrical conductor is a measure of the difficulty to pass an electric current through that conductor.

An electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit (e.g. a semiconductor, an electrolyte, a vacuum or air).

Electromotive force, also called emf (denoted and measured in volts), is the voltage developed by any source of electrical energy such as a battery or dynamo.

In physics and chemistry, the Faraday constant, denoted by the symbol F and named after Michael Faraday, is the magnitude of electric charge per mole of electrons.

An inductor, also called a coil or reactor, is a passive two-terminal electrical component which resists changes in electric current passing through it.

Joule heating, also known as ohmic heating and resistive heating, is the process by which the passage of an electric current through a conductor releases heat.

Ohm's law states that the current through a conductor between two points is directly proportional to the voltage across the two points.

Voltage, electric potential difference, electric pressure or electric tension (formally denoted ∆V or ∆U, but more often simply as V or U, for instance in the context of Ohm's or Kirchhoff's laws) is the difference in electric potential energy between two points per unit electric charge.

In electrical engineering, admittance is a measure of how easily a circuit or device will allow a current to flow.

The elementary charge, usually denoted as e or sometimes q, is the electric charge carried by a single proton, or equivalently, the magnitude of the electric charge carried by a single electron, which has charge −e.

Cathode rays (also called an electron beam or e-beam) are streams of electrons observed in vacuum tubes.

(Not to be confused with bundle conductors used in high-voltage power transmission.) Aerial bundled cables (also aerial bundled conductors or simply ABC) are overhead power lines using several insulated phase conductors bundled tightly together, usually with a bare neutral conductor.

AC power plugs and sockets are devices that allow electrically operated equipment to be connected to the primary alternating current (AC) power supply in a building.

A circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overcurrent or overload or short circuit.

A telluric current (from Latin tellūs, "earth"), or Earth current, is an electric current which moves underground or through the sea.

A temperature coefficient describes the relative change of a physical property that is associated with a given change in temperature.

Electrode potential, E, in electrochemistry, according to an IUPAC definition, is the electromotive force of a cell built of two electrodes: * on the left-hand side is the standard hydrogen electrode, and * on the right-hand side is the electrode the potential of which is being defined.

In an electrical system, a ground loop or earth loop is an equipment and wiring configuration in which there are multiple paths for electricity to flow to ground.

Dry contact may mean any of the following in electronics: * No current: A dry contact is the synonym of volt free - it is not "wetted" by a voltage source.

Electric potential energy, or electrostatic potential energy, is a potential energy (measured in joules) that results from conservative Coulomb forces and is associated with the configuration of a particular set of point charges within a defined system.

The term high voltage usually means electrical energy at voltages high enough to inflict harm on living organisms.

The electrostatic system of units is a system of units used to measure electrical quantities of electric charge, electric current, and voltage within the centimeter-gram-second (or "CGS") system of metric units.

The history of electromagnetic theory begins with ancient measures to understand atmospheric electricity, in particular lightning.