{"id":726,"date":"2007-07-19T09:33:56","date_gmt":"2007-07-19T06:33:56","guid":{"rendered":"http:\/\/www.fyysika.ee\/wordpress\/?p=726"},"modified":"2011-08-08T23:36:21","modified_gmt":"2011-08-08T20:36:21","slug":"magnet-ulijuhtivas-torus","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=726","title":{"rendered":"Magnet \u00fclijuhtivas torus"},"content":{"rendered":"<p lang=\"et-EE\" style=\"margin-bottom: 0cm; text-align: justify; font-weight: bold;\">K\u00fcllap on m\u00f5nedki<br \/>\nn\u00e4inud demoeksperimenti vertikaalses vasktorus \u00fcliaeglaselt<br \/>\nlangeva neod\u00fc\u00fcmmagnetiga. Magneti langemist pidurdab<br \/>\nmuutuva magnetv\u00e4lja m\u00f5jul toru seintes tekkinud<br \/>\nkeerisvoolude magnetv\u00e4li, mille tulemusel magnet omandab<br \/>\ntasakaalulise kiiruse umbes 0,1 m\/s. \u00dcldistest f\u00fc\u00fcsikalistest<br \/>\narusaamadest l\u00e4htuvalt on loomulik oletada, et mida v\u00e4iksem<br \/>\non toru materjali eritakistus, seda aeglasemalt magnet langeb. Nagu<br \/>\nsee ka tegelikult on. Aga kui vasktoru asendada \u00fclijuhiga? Kas<br \/>\nsiis peaks magnet torus seisma j\u00e4\u00e4ma? M\u00f5neti<br \/>\n\u00fcllatavalt on olukord hoopis vastupidine \u2013 piisavalt kaugel<br \/>\ntoru otstest (ja \u00f5hutakistust mitte arvestades) liigub magnet<br \/>\n\u00fclijuhtivas torus vaba langemise kiirendusega.<\/p>\n<div style=\"text-align: justify;\">&nbsp;<\/div>\n<p style=\"margin-bottom: 0cm; text-align: justify;\"><span lang=\"et-EE\">Tulemus on<br \/>\nm\u00f5istetavam, kui vaadelda toru liikumist <i>paigalseisva<br \/>\n<\/i>magneti suhtes. \u00dclijuhtiv toru on ideaalne diamagneetik,<br \/>\nmille sisse magnetv\u00e4li ei suuda tungida. Seet\u00f5ttu m\u00f5jub<br \/>\ntalle v\u00e4lises magnetv\u00e4ljas j\u00f5ud, mis p\u00fc\u00fcab<br \/>\nviia \u00fclijuhti n\u00f5rgemasse v\u00e4lja. Kui toru on magneti<br \/>\nm\u00f5\u00f5tmetega v\u00f5rreldes piisavalt pikk ja magnet<br \/>\nasetseb toru otstest piisavalt kaugel, siis ei muuda magneti ja toru<br \/>\nsuhtelised nihked oluliselt s\u00fcsteemi energiat  \u2013 torule m\u00f5juv<br \/>\nj\u00f5ud on v\u00e4ga v\u00e4ike (raskusj\u00f5udu arvestamata).<br \/>\nK\u00fcll tuleb j\u00f5udu kulutada magneti torusse surumiseks \u2013<br \/>\nvaid oma raskuse ja magnetj\u00f5udude m\u00f5jul v\u00f5ibki<br \/>\nta j\u00e4\u00e4da toru \u00fclemise otsa kohale h\u00f5ljuma<br \/>\n(Meissneri levitatsioon). Erinevus harilike ja \u00fclijuhtide vahel<br \/>\nseisneb selles, et esimesel juhul magnetile m\u00f5juv j\u00f5ud<br \/>\ns\u00f5ltub oluliselt ta kiirusest, teisel juhul aga asendist<br \/>\n\u00fclijuhi suhtes. Selle p\u00f5hjuseks on asjaolu, et harilikus<br \/>\njuhis tekitatud keerisvoolud sumbuvad praktiliselt hetkeliselt, kui<br \/>\nmagnetv\u00e4li enam ei muutu, \u00fclijuhis tekkinud vool on aga<br \/>\nsumbumatu. <\/span>\n<\/p>\n<div style=\"text-align: justify;\">&nbsp;<\/div>\n<p style=\"margin-bottom: 0cm; text-align: justify;\"><span lang=\"et-EE\">Et asi siiski liiga<br \/>\nlihtne ei oleks, siis m\u00e4rgime, et II liiki \u00fclijuhtides,<br \/>\nmille hulka kuuluvad ka kuulsad k\u00f5rgtemperatuursed \u00fclijuhid,<br \/>\nm\u00f5jutavad magneti liikumist veel ka magnetvorteksid ja nende<br \/>\nl\u00f5ksustumine (ik <i>pinning<\/i>) \u00fclijuhi ja<br \/>\nmagnetmaterjali defektidel. See pidurdab magneti liikumist<br \/>\nkirjeldatud \u201ctorukatses\u201d ka pika \u00fclijuhtiva toru sisemuses.<\/span><\/p>\n<div style=\"text-align: justify;\">&nbsp;<\/div>\n<p lang=\"et-EE\" style=\"margin-bottom: 0cm; text-align: justify;\">Allikas:<br \/>\nhttp:\/\/physicsweb.org\/articles\/news\/10\/9\/13\/1<\/p>\n<div style=\"text-align: justify;\">&nbsp;<\/div>\n<p lang=\"et-EE\" style=\"margin-bottom: 0cm; text-align: justify;\">Koostas: Jaak Kikas<\/p>\n","protected":false},"excerpt":{"rendered":"<p>K\u00fcllap on m\u00f5nedki n\u00e4inud demoeksperimenti vertikaalses vasktorus \u00fcliaeglaselt langeva neod\u00fc\u00fcmmagnetiga. Magneti langemist pidurdab muutuva magnetv\u00e4lja m\u00f5jul toru seintes tekkinud keerisvoolude magnetv\u00e4li, mille tulemusel magnet omandab tasakaalulise kiiruse umbes 0,1 m\/s. \u00dcldistest f\u00fc\u00fcsikalistest arusaamadest l\u00e4htuvalt on loomulik oletada, et mida v\u00e4iksem on toru materjali eritakistus, seda aeglasemalt magnet langeb. Nagu see ka tegelikult on. Aga kui [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[16],"tags":[],"class_list":{"0":"post-726","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-teadusuudis","7":"entry"},"_links":{"self":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/726","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=726"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/726\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=726"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=726"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=726"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}