Elektricitet

Ved elektricitet forstås en række fysiske fænomener forbundet ved en tilstedeværelse og en strøm af elektrisk ladede partikler. Elektricitet har en bred vifte af effekter, f.eks. lyn, statisk elektricitet, elektromagnetisk induktion og elektrisk strøm. Desuden muliggør elektricitet dannelse og opfangning af elektromagnetisk stråling såsom radiobølger.

Effekter

Såkaldt statisk elektricitet er ikke en elektronstrøm. Det skyldes et over- eller underskud af elektroner i forhold til positive kernepartikler (protoner):^{[kilde mangler]}

Når der er et overskud af elektroner, siges objektet at være "negativt ladet".
Når der er et underskud af elektroner, siges objektet at være "positivt ladet".
Når antallet af elektroner og antallet af protoner er ens, siges objektet at være "elektrisk neutralt".

Elektriske fænomener i naturen:

Lyn
Kuglelyn - Sandsynligvis induceret af elektricitet.
Elektroception ^(en) - Mange dyr som f.eks. næbdyret, hajer og maller er følsomme og har derfor en sans for elektriske felter. Denne sans kan anvendes til at finde byttedyr.
Bioelektricitet - Nogle dyr kan også generere et stærkt elektrisk felt som f.eks. elektriske ål, elektriske maller, elrokke.

Elektricitet kan f.eks. genereres ved hjælp af følgende transducere:

Elektrokemiske:

Elektromekaniske:

dynamo
piezoelektrisk keramik. Visse elektroniske lightere.
piezoelektrisk kvarts
Van de Graaff-generator ^(no)

Elektroakustiske:

Elektromagnetiske (baseret primært på den fotoelektriske effekt):

Lysdiode. En lysdiode kan faktisk virke som en lille solcelle^{[kilde mangler]}.
Radioantenne
Solcelle

Elektrotermiske:

Peltier-element ^(de)

Se også

Søsterprojekter med yderligere information:

Kilder/referencer

↑ Jan 9, 2014, physicsworld.com: Burning soil fuels ball lightning Arkiveret 10. januar 2014 hos Wayback Machine Citat: "...In 2000 John Abrahamson and James Dinniss of the University of Canterbury in New Zealand suggested that ball lightning is caused by lightning striking silicon-rich soil..."
↑ University of Florida. (2006, February 6). Scientists Trace Origin Of Shark's Electric Sense. ScienceDaily Arkiveret 23. september 2015 hos Wayback Machine Citat: "..."Sharks have a network of electrosensory cells that allows them to hunt by detecting electrical signals generated by prey," said Martin Cohn, a developmental biologist with the departments of zoology and anatomy and cell biology, and the UF Genetics Institute. "That doesn't mean they can only detect electric fish. They can sense electricity generated by a muscle twitch, even if it's the weak signal of a flounder buried under sand."..."
↑ Washington University School of Medicine. (2008, May 7). Platypus Genome Explains Animal's Peculiar Features; Holds Clues To Evolution Of Mammals. ScienceDaily Arkiveret 11. juli 2015 hos Wayback Machine Citat: "...the platypus also sports a duck-like bill that holds a sophisticated electrosensory system used to forage for food underwater..."
↑ University of Texas at Austin. (2009, September 29). Electric Fish Plug In To Communicate. ScienceDaily Arkiveret 6. september 2015 hos Wayback Machine Citat: "...They do so at night, while trying to avoid predators such as catfish that sense the electric fields..."
↑ Washington University in St. Louis. (2015, August 4). Fish that have their own fish finders. ScienceDaily Arkiveret 5. august 2015 hos Wayback Machine Citat: "...The fish with nuanced signal discrimination can glean a stunning amount of information from electric signals, including the signaler's species, sex, age, relative dominance status, and possibly even individual identity. They can also detect emotional states, such as aggression, submission, courtship and active exploration. The fish with the simpler communication system were less studied and less well understood..."

Eksterne henvisninger

Elsystemet lige nu Arkiveret 28. november 2011 hos Wayback Machine (aktuelt elforbrug og -produktion i Danmark, kræver Flash)
Se oversigt over danske vindmøller, der producerer billig el af Vindstød Arkiveret 4. november 2016 hos Wayback Machine
Prisen på el Arkiveret 27. december 2016 hos Wayback Machine kan blive negativ eller gratis ved særlige vejr- og forbrugsforhold.

[1] Jan 9, 2014, physicsworld.com: Burning soil fuels ball lightning Arkiveret 10. januar 2014 hos Wayback Machine Citat: "...In 2000 John Abrahamson and James Dinniss of the University of Canterbury in New Zealand suggested that ball lightning is caused by lightning striking silicon-rich soil..."

[2] University of Florida. (2006, February 6). Scientists Trace Origin Of Shark's Electric Sense. ScienceDaily Arkiveret 23. september 2015 hos Wayback Machine Citat: "..."Sharks have a network of electrosensory cells that allows them to hunt by detecting electrical signals generated by prey," said Martin Cohn, a developmental biologist with the departments of zoology and anatomy and cell biology, and the UF Genetics Institute. "That doesn't mean they can only detect electric fish. They can sense electricity generated by a muscle twitch, even if it's the weak signal of a flounder buried under sand."..."

[3] Washington University School of Medicine. (2008, May 7). Platypus Genome Explains Animal's Peculiar Features; Holds Clues To Evolution Of Mammals. ScienceDaily Arkiveret 11. juli 2015 hos Wayback Machine Citat: "...the platypus also sports a duck-like bill that holds a sophisticated electrosensory system used to forage for food underwater..."

[4] University of Texas at Austin. (2009, September 29). Electric Fish Plug In To Communicate. ScienceDaily Arkiveret 6. september 2015 hos Wayback Machine Citat: "...They do so at night, while trying to avoid predators such as catfish that sense the electric fields..."

[5] Washington University in St. Louis. (2015, August 4). Fish that have their own fish finders. ScienceDaily Arkiveret 5. august 2015 hos Wayback Machine Citat: "...The fish with nuanced signal discrimination can glean a stunning amount of information from electric signals, including the signaler's species, sex, age, relative dominance status, and possibly even individual identity. They can also detect emotional states, such as aggression, submission, courtship and active exploration. The fish with the simpler communication system were less studied and less well understood..."