Electricity is the set of physical phenomena associated with the presence and flow of electric charge. Electricity gives a wide variety of well-known effects, such as lightning, static electricity, electromagnetic induction and the flow of electrical current. In addition, electricity permits the creation and reception of electromagnetic radiation such as radio waves.
In electricity, charges produce electromagnetic fields which act on other charges. Electricity occurs due to several types of physics:
- electric charge: a property of some subatomic particles, which determines their electromagnetic interactions. Electrically charged matter is influenced by, and produces, electromagnetic fields.
- electric current: a movement or flow of electrically charged particles, typically measured in amperes.
- electric field (see electrostatics): an especially simple type of electromagnetic field produced by an electric charge even when it is not moving (i.e., there is no electric current). The electric field produces a force on other charges in its vicinity. Moving charges additionally produce a magnetic field.
- electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts.
- electromagnets: electrical currents generate magnetic fields, and changing magnetic fields generate electrical currents
In electrical engineering, electricity is used for:
- electric power where electric current is used to energise equipment
- electronics which deals with electrical circuits that involve active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies.
Electrical phenomena have been studied since antiquity, though advances in the science were not made until the seventeenth and eighteenth centuries. Practical applications for electricity however remained few, and it would not be until the late nineteenth century that engineers were able to put it to industrial and residential use. The rapid expansion in electrical technology at this time transformed industry and society. Electricity's extraordinary versatility as a means of providing energy means it can be put to an almost limitless set of applications which include transport, heating, lighting, communications, and computation. Electrical power is the backbone of modern industrial society, and is expected to remain so for the foreseeable future.
The word electricity is from the New Latin ēlectricus, "amber-like", coined in the year 1600 from the Greek ήλεκτρον (electron) meaning amber, because electrical effects were produced classically by rubbing amber.
Famous quotes containing the word electricity:
“There are two great unknown forces to-day, electricity and woman, but men can reckon much better on electricity than they can on woman.”
—Josephine K. Henry, U.S. suffragist. As quoted in History of Woman Suffrage, vol. 4, ch. 15, by Susan B. Anthony and Ida Husted Harper (1902)