The Online Encyclopedia and Dictionary






Static electricity

Static electricity or electrostatics is a field of science and a class of phenomena involving the imbalanced charge present on an object, typically referring to charge with voltage of sufficient magnitude to produce visible attraction, repulsion, and sparks.


The presence of surface charge imbalance means that the objects will exhibit attractive or repulsive forces. Static electricity can be generated by touching two differing surfaces together and then separating them because of contact electrification and the triboelectric effect. Friction between two objects generates a great amount of static electric effects both because of the many instances of contact and separation and because of differential heating of tiny protrusions. Usually, substances that don't conduct electricity (insulators) are good at both generating and holding a surface charge. Some examples of these substances are rubber, plastic, glass, and pith. Conductive objects only rarely will generate charge imbalance, for example when a metal surface is impacted by solid or liquid nonconductors. The charge that is transferred during contact electrification is stored on the surface of each object. Static electric generators, devices which produce very high voltage at very low current, are frequently used for classroom physics demonstrations.

Note that the presence of electric current does not detract from the electrostatic forces nor from the sparking, from the corona discharge, or other phenomena. In other words, electric current is not the opposite of static electricity, and both phenomena can exist together at the same time.

Natural electrostatic phenomena are most familiar as an occasional annoyance in seasons of low humidity, but can be destructive and harmful in some situations (e.g. electronics manufacturing.) When working in direct contact with integrated circuit electronics (especially delicate MOSFETs), or in the presence of flammable gas, care must be taken to avoid accumulating and discharging a static charge.

See also





External links

Last updated: 10-24-2005 18:19:15
The contents of this article are licensed from under the GNU Free Documentation License. How to see transparent copy