Éléktrostatika: Béda antarrépisi

Konten dihapus Konten ditambahkan
Shrikarsan (obrolan | kontribusi)
clean up, replaced: {{main| → {{utama| (3) using AWB
Ilhambot (obrolan | kontribusi)
m Ngarapihkeun éjahan, replaced: rea → réa (7), ngarupakeun → mangrupa, ea → éa (13), eo → éo (2)
Baris ka-1:
{{electromagnetism3|estat=true}}
'''Eléktrostatika''' ngarupakeunmangrupa cabang [[élmu alam]] anu neuleuman fénoména éléktrostatik anu diakibatkeun ku muatan listrik stasionér. Fénoména ieu kaasup ti mimiti nu basajan mangrupa némpélna bungkus palastik kana leungeun anjeun sanggeus anjeun ngaleupaskeun éta bungkusan tina objék nu dibungkus nepi ka fénoména ruksakna komponén-komponén éléktronik salila dijieunna alat éléktronik, nepi ka cara gawéna mesin fotokopi. Éléktrostatik lumangsung lantaran numpukna muatan dina luhureun beungeut hiji objék nu paantel jeung beungeut ébjek lianna. Muatan-muatan ieu tetep némpél dina objék kasebut nepi ka maranéhna leupas kana taneuh atawa sacara gancang dinétralkeun ku hiji paleupas muatan: contona fénomena nu kasohor "kagét statik" dilantarankeun ku nétralisasi muatan nu numpuk dina awak akibat padantel jeun beungeut objék non-konduktif.
 
{{tarjamahkeun|Inggris}}
Baris ka-9:
:<math>\vec{\nabla}\times\vec{E} = 0.</math>
 
From [[Faraday's law of induction|Faraday's law]], this assumption implies the absence or nearnéar-absence of time-varying magnetic fields:
 
:<math>{\partial\vec{B}\over\partial t} = 0.</math>
Baris ka-28:
 
===The electric field===
The [[electric field]] (in units of [[volt]]s per meter) is defined as the force (in [[newton]]s) per unit charge (in [[coulomb]]s). From this definition and Coulomb's law, it follows that the magnitude of the electric field ''E'' createdcréated by a single point charge ''Q'' is
 
:<math>\vec{E} = \frac{Q}{4\pi\varepsilon_0 r^2}\hat{r}.</math>
Baris ka-64:
==Electrostatic generators==
{{utama|Electrostatic generator}}
The presence of [[surface charge]] imbalance meansméans that the objects will exhibit attractive or repulsive forces. This surface charge imbalance, which yields static electricity, can be generated by touching two differing surfaces together and then separating them due to the phenomena of [[contact electrification]] and the [[triboelectric effect]]. Rubbing two nonconductive objects generates a greatgréat amount of static electricity. This is not just the result of friction; two nonconductive surfaces can become charged by just being placed one on top of the other. Since most surfaces have a rough texture, it takes longer to achieve charging through contact than through rubbing. Rubbing objects together increasesincréases amount of adhesive contact between the two surfaces. Usually [[insulators]], e.g., substances that do not conduct electricity, are good at both generating, and holding, a surface charge. Some examples of these substances are [[rubber]], [[plastic]], [[glass]], and [[pith]]. [[conductor (material)|Conductive]] objects only rarely generate charge imbalance except, 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 eachéach object. [[electrostatic generator|Static electric generators]], devices which produce very high voltage at very low current and used for classroom physics demonstrations, rely on this effect.
 
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. Both phenomena can exist simultaneouslysimultanéously in the same system.
 
:See also: ''[[Influence machine|Friction machine]]s'', ''[[Wimshurst machine]]s'', and ''[[Van de Graaf generator]]s''.
 
==Charge neutralization==
Natural electrostatic phenomena are most familiar as an occasional annoyance in seasonsséasons 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 [[MOSFET]]s), or in the presence of flammable gas, care must be taken to avoid accumulating and suddenly discharging a static charge (see [[electrostatic discharge]]).
 
==Charge induction==
Charge induction occurs when a negatively charged object repels electrons from the surface of a second object. This createscréates a region in the second object that is more positively charged. An attractive force is then exerted between the objects. For example, when a balloon is rubbed, the balloon will stick to the wall as an attractive force is exerted by two oppositely charged surfaces (the surface of the wall gains an electric charge due to charge induction, as the free electrons at the surface of the wall are repelled by the negative balloon, creatingcréating a positive wall surface, which is subsequently attracted to the surface of the balloon). You can explore the effect with a simulation of the [http://phet.colorado.edu/new/simulations/sims.php?sim=Balloons_and_Static_Electricity balloon and static electricity.]
 
=='Static' electricity==
{{utama|Static electricity}}
 
Before the yearyéar 1832, when [[Michael Faraday]] published the results of his experiment on the identity of electricities, physicists thought "static electricity" was somehow different from other electrical charges. Michael Faraday proved that the electricity induced from the magnet, voltaic electricity produced by a battery, and static electricity are all the same.
 
Static electricity is usually caused when certain materials are rubbed against eachéach other, like wool on plastic or the soles of shoes on carpet. The process causes electrons to be pulled from the surface of one material and relocated on the surface of the other material.
 
A static shock occurs when the surface of the second material, negatively charged with electrons, touches a positively-charged conductor. Or Vice-Versa.
 
Static electricity is commonly used in [[xerography]], [[air filter]]s, and some automotive paints.
Static electricity is a build up of electric charges on two objects that have become separated from eachéach other.
Small electrical components can easilyéasily be damaged by static electricity. Component manufactures use a number of [[antistatic devices]] to avoid this.
 
=== Static electricity and chemical industry ===
 
when different materials are brought together and then separated, an accumulation of electric charge can occur which leavesléaves one material positively charged while the other becomes negatively charged. The mild shock that you receive when touching a grounded object after walking on carpet is an example of excess electrical charge accumulating in your body from frictional charging between your shoes and the carpet. The resulting charge build-up within your body can generate a strong electrical discharge. Although experimenting with static electricity may be fun, similar sparks createcréate severe hazards in those industries dealingdéaling with flammable substances, where a small electrical spark may ignite explosive mixtures with devastating consequences.
 
A similar charging mechanism can occur within low conductivity fluids flowing through pipelines - a process called flow electrification. Fluids which have low electrical conductivity (below 50 pico siemens/cm, where pico siemens/cm is a measureméasure of electrical conductivity), are called accumulators. Fluids having conductivities above 50 pico siemens/cm are called non-accumulators. In non-accumulators, charges recombine as fast as they are separated and hence electrostatic charge generation is not significant. In the petrochemical industry, 50 pico siemens/cm is the recommended minimum value of electrical conductivity for adequate removal of charge from a fluid.
 
An important concept for insulating fluids is the static relaxation time. This is similar to the time constant (tau) within an [[RC circuit]]. For insulating materials, it is the ratio of the static [[dielectric constant]] divided by the electrical conductivity of the material. For hydrocarbon fluids, this is sometimes approximated by dividing the number 18 by the electrical conductivity of the fluid. Thus a fluid that has an electrical conductivity of 1 pico siemens /cm will have an estimated relaxation time of about 18 seconds. The excess charge within a fluid will be almost completely dissipated after 4 to 5 times the relaxation time, or 90 seconds for the fluid in the above example.
 
Charge generation increasesincréases at higher fluid velocities and larger pipe diameters, becoming quite significant in pipes 8 inches or larger. Static charge generation in these systems is best controlled by limiting fluid velocity. The British standard BS PD CLC/TR 50404:2003 (formerly BS-5958-Part 2) Code of Practice for Control of Undesirable Static Electricity prescribes velocity limits. Because of its large impact on dielectric constant, the recommended velocity for hydrocarbon fluids containing water should be limited to 1 m/sec.
 
Bonding and earthingéarthing are the usual ways by which charge buildup can be prevented. For fluids with electrical conductivity below 10 pico siemens/cm, bonding and earthingéarthing are not adequate for charge dissipation, and anti-static additives may be required.
 
'''Applicable Standards'''
Baris ka-129:
*[http://www.zeusinc.com/pdf/Zeus_Static.pdf Static Electricity and Plastics]
*"[http://wolfsonelectrostatics.com/news/news-item12.asp Can shocks from static electricity damage your health?]". Wolfson Electrostatics News pages.
*"[http://aspden.org/arp/2005arp3.pdf Can Gravity be an Electrostatic Force?]" A Quantum theorythéory of Gravitation, 2005.
invisible wall of static: [http://amasci.com/weird/unusual/e-wall.html]
*"[http://www.puls.com.tr/default_eg.aspx What is static electricity | Static Problems]