Static electricity . It is a phenomenon that is due to an accumulation of electrical charges on an object. This accumulation can lead to an electric shock when the object comes into contact with another.
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- 1 History
- 2 Origin
- 3 Utility
- 4 Induced charge
- 5 Applications
- 6 Dangers
- 7 Sources
Before 1832 , when Michael Faraday published the results of his experiments on the identity of electricity , physicists thought that “static electricity” was somewhat different from other electrical charges. Michael Faraday demonstrated that electricity induced from a magnet , electricity produced by a battery , and static electricity are all the same.
Static electricity occurs when certain materials are rubbed against each other, such as wool against plastic or shoe soles against the carpet , where the rubbing process causes electrons to be removed from the surface of a material and relocated to the surface of the other material that offers more favorable energy levels , or when ionized particles are deposited in a material, as for example, occurs in satellites when receiving the flow of the solar wind and the Van Allen radiation belts . The electrification capacity of bodies by friction is calledtriboelectric effect , there is a classification of the different materials called triboelectric sequence .
Static electricity is commonly used in xerography , in filters for air , and some automotive paints. Small components in electrical circuits can be easily damaged by static electricity. Manufacturers use a number of antistatic devices to prevent damage.
Rubbing two non-conductive objects generates a large amount of static electricity. This effect is not due to friction since two non-conductive surfaces can be charged by resting on each other. It is because rubbing two objects increases the contact between the two surfaces. Insulators are usually good for generating and preserving surface charges. Some examples of these substances are rubber , plastic or glass . Conductive objects rarely generate load imbalances, except, for example, when a metal surfaceis hit by a solid or non-conductive liquid. The charge that is transferred during contact electrification is stored to the surface of each object, in order to be as separate as possible and thus reduce the repulsion between charges.
The induced charge occurs when a charged object repels or attracts electrons from the surface of a second object. This creates a region in the second object that is most positively charged, creating an attractive force between the objects. For example, when you rub a balloon , the balloon will stick to the wall due to the attractive force exerted by two surfaces with opposite charges (the wall surface gains an induced electrical charge since the free electrons on the wall surface are repelled by the electrons the balloon has gained by rubbing, creating a positively charged surface on the wall, which then attracts the surface of the balloon.)
In everyday electrical effects, not those of particle accelerators , only electrons move. The positive charge of the atom , given by the protons , remains immobile.
Static electricity is commonly used in xerography where a powder pigment (dry ink or toner) is fixed on previously charged areas making the printed image visible.
In electronics , static electricity causes numerous damage to components, so operators must take measures to discharge any static electricity they may have acquired. This can occur to a person by rubbing the soles of shoes (made of materials such as rubber) against cloth or carpet floors. In aviation, when landing an airplane for safety, it must be unloaded.
In cars also the electrification can occur at the large circular speed (better wet air leads loads) in dry air, so that also require security measures to prevent electrical sparks. Tanker trucks that transport flammable substances use at the rear a chain that they drag, which works as physical ground. It is thought that the explosion of a rocket in 2003 in Brazil was due to sparks caused by static electricity.
The fundamental danger is electric shock , with the consequent risk of ignition by sparks in flammable atmospheres , for example, risk of explosion in oil tankers . It is very important to previously study the security methods to avoid risks