The intrinsic property of matter giving rise to all electric phenomena, occurring in two forms arbitrarily given positive and negative algebraic signs and measured in coulombs

The product of potential difference and current in a direct-current circuit

The SI unit of power, equal to one joule per second or to the power represented by a current of one ampere flowing across a potential difference of one volt

An amount of power, esp. the power required to operate an electrical device or appliance, expressed in watts

The strength of an electric current measured or expressed in amperes; analogous to the rate of water flow

A unit of power, equal to 1,000 watts

A unit of energy, equal to the energy transferred or expended by one kilowatt in one hour; a common unit of electric power consumption

Potential difference or electromotive force expressed in volts; analogous to pressure in water flow

The rate of flow of electric charge in a circuit per unit time, measured in amperes

The basic SI unit of electric current, equivalent to a flow of one coulomb per second or to the steady current produced by one volt applied across a resistance of one ohm

The opposition of a conductor to the flow of current, causing some of the electric energy to be transformed into heat and usually measured in ohms

The SI unit of potential difference and electromotive force, defined as the difference of electric potential between two points of a conductor carrying a constant current of one ampere, when the power dissipated between the points is equal to one watt

The SI unit of electrical resistance, equal to the resistance of a conductor in which a potential difference of one volt produces a current of one ampere

The complete path of an electric current, including the source of electric energy

The law that for any circuit the electric current is directly proportional to the voltage and inversely proportional to the resistance

The principle that the rate of production of heat by a direct current is directly proportional to the resistance of the circuit and to the square to the current

An arrangement of components in an electric circuit in which the same current flows through each component in turn without branching

An arrangement of components in an electric circuit in which all positive terminals are connected to one conductor and all negative terminals are connected to a second conductor, the same voltage being applied to each component

The resistance per unit length of a substance with a unit cross-sectional area

A measure of the ability of a substance to conduct electric current, equal to the reciprocal of the resistivity of the substance

A group of two or more cells connected together to produce electric current

A non-metallic conducting medium in which current is carried by the movement of ions

A conductor through which a current enters or leaves a non-metallic medium

A device for converting chemical into electric energy, usually consisting of a receptacle with electrodes in an electrolyte

The negative terminal of a primary cell or storage battery

The positive terminal of a primary cell or storage battery

A machine that converts mechanical energy into electrical energy

A machine that converts electric power into mechanical energy

The main current-carrying winding of a motor or generator in which electromotive force is induced

A copper or carbon conductor serving to maintain electric contact between fixed and moving elements in a motor or generator

A generator for producing alternating current

A mass of iron or other ferrous material in an electromagnet, induction coil, or transformer, serving to concentrate and intensify the magnetic field resulting from a current in a surrounding coil

A conductor wound in a spiral form to introduce inductance into a circuit

An electric device consisting of two or more windings wound on the same core, which employs the principle of mutual induction to convert variations of alternating current in a primary circuit into variations of voltage and current in a secondary circuit

An electric current flowing in one direction only and having a magnitude that does not vary or varies only slightly

A transformer having fewer turns in the primary winding than in the secondary, serving to transform low voltage to high voltage

A transformer having greater turns in the primary winding than in the secondary, serving to transform high voltage to low voltage

The supplying of utilities, such as water, gas, and electricity, required or demanded by the public

The decrease in voltage between two points on a power line, usually caused by resistance or leakage along the line

The portion of a service conductor extending from a service drop or service lateral to the service equipment of a building

A meter for measuring and recording the quantity of electric power consumed with respect to time

Operated on, powered by, or transmitting high voltage

An auxiliary power station where electrical current is converted, as from DC to AC, or where voltage is stepped up or down

The voltage supplied by a power line, measured at the point of use

Any of several conductors extending from a main power line or transformer to the service equipment of a building

The overhead portion of service conductors extending from the nearest utility pole of a building

The underground portion of service conductors extending from a main power line or transformer to a building

Any of the conductors extending from the service equipment to various distribution points in a building

A freestanding enclosure housing a disconnect switch, a step-down transformer, and switchgear for a number of electric circuits

A room containing the service equipment for a building

The equipment necessary for controlling, metering, and protecting the electric power supply to a building, located near the entrance of the service conductors and usually consisting of a main disconnect switch and secondary switched, fuses, and circuit breakers

One or a group of panels on which are mounted switches, overcurrent devices, metering instruments, and buses for controlling and protecting a number of electric circuits. Also called switchgear

A fire-rated room housing a transformer and auxiliary equity for a large building, usually located on grade or below ground and ventilated directly to the outside air

A generator for providing emergency power during a power outage

An emergency system designed to provide power automatically and instantaneously upon failure of the normal power supply