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The fact that the force (and hence the field) can be calculated by summing over all the contributions due to individual source particles is an example of the superposition principle. The electric field produced by a distribution of charges is given by the volume charge density ρ ( r ) {\displaystyle \rho (\mathbf {r} )} and can be obtained by ...
Sparks — Electrical breakdown of a medium that produces an ongoing plasma discharge, similar to the instant spark, resulting from a current flowing through normally nonconductive media such as air. Telluric currents — Extremely low frequency electric current that occurs naturally over large underground areas at or near the surface of the Earth.
The feeling of an electric shock is caused by the stimulation of nerves as the current flows through the human body. The energy stored as static electricity on an object varies depending on the size of the object and its capacitance, the voltage to which it is charged, and the dielectric constant of the surrounding medium.
The electromagnetic force is responsible for many of the chemical and physical phenomena observed in daily life. The electrostatic attraction between atomic nuclei and their electrons holds atoms together. Electric forces also allow different atoms to combine into molecules, including the macromolecules such as proteins that form the basis of life.
In the 19th and early 20th centuries, electricity was not part of the everyday life of many people, even in the industrialised Western world. The popular culture of the time accordingly often depicted it as a mysterious, quasi-magical force that can slay the living, revive the dead or otherwise bend the laws of nature.
There can be electric fields of up to 160kV/m with moderate wind conditions, which leads to Coulomb forces of about the same magnitude as gravity. [129] There does not need to be air present, significant charging can occur, for instance, on airless planetary bodies. [ 130 ]
Coupled with hurricane-force winds, firefighters didn't stand a chance when a spark met its soulmate and whipped up a blaze that instantly took off as if it were taking part in a marathon. #4 ...
An early example of regular use of human-powered electrical equipment is in early telephone systems; current to ring the remote bell was provided by a subscriber cranking a handle on the telephone, which turned a small magneto generator. Human-powered devices are useful as emergency equipment, when natural disaster, war, or civil disturbance ...