Electricity
lastmod 2025-11-05created 2020-10-052 edits
Electricity is the set of physical phenomena associated with the presence and motion of electric charge. Electricity is the cause of everyday effects such as lightning, static electricity, electromagnetic induction, and electric current. Electricity can also emit and receive electromagnetic radiation such as radio waves.
Physics
Electricity as studied in physics appears in various forms, such as the following.
- Electric charge: the property of some subatomic particles that determines their electromagnetic interactions. Electrically charged matter produces electromagnetic fields and is also influenced by them. Charge can be negative or positive.
- Electric field (see electrostatics): charges are surrounded by an electric field. The electric field produces a force on other charges. Changes in the electric field travel at the speed of light.
- Electric potential: the capacity of an electric field to do work on an electric charge, typically measured in volts.
- Electric current: the movement or flow of electrically charged particles, typically measured in amperes.
- Electromagnets: moving charges produce a magnetic field. Electric currents also produce magnetic fields, and changing magnetic fields produce electric currents.
Electrical engineering
In electrical engineering, electricity is used as follows.
- Electric power: supplies energy using electric current.
- Electronics: deals with circuits made of active components such as vacuum tubes, transistors, diodes, and integrated circuits, and associated passive component technologies.
- Electricity has been studied since antiquity, although scientific advances did not come until the 17th and 18th centuries. It was not until the late 19th century that electrical engineers were able to put electricity to industrial and residential use. This period saw a rapid expansion in the development of electrical technology. The extraordinary versatility of electricity as a source of energy means it can be put to an almost limitless set of applications, including transport, heating, lighting, communications, and computation. Electric power is the backbone of modern industrial society.