electricity
electricity Form of energy associated with static or moving charges. Charge has two forms – positive and negative. Like charges repel, and unlike attract; as described by Charles Coulomb in Coulomb's law. Electric charges are acted upon by forces when they move in a magnetic field, this movement generates an opposing magnetic field (Faraday's laws). Electricity and magnetism are different aspects of electromagnetism. The flow of charges constitutes a current, which in a conductor consists of negatively charged electrons. For an electric current to exist in a conductor there must be an electromotive force (emf) or potential difference between the ends of the conductor. If the source of potential difference is a battery, the current flows in one direction as a direct current (DC). If the source is the mains, the current reverses direction twice every cycle, as alternating current (AC). The ampere is the unit of current, the coulomb is the unit of charge, the ohm the unit of resistance and the volt is the unit of electromotive force. Ohm's law and the laws of Kirchhoff are the basic means of calculating circuit values.
More From encyclopedia.com
NEARBY TERMS
electricity
