{"id":397,"date":"2013-11-18T17:54:34","date_gmt":"2013-11-18T17:54:34","guid":{"rendered":"https:\/\/blogs.ua.es\/ffic\/?p=397"},"modified":"2013-11-26T11:38:16","modified_gmt":"2013-11-26T11:38:16","slug":"camp-electric-3","status":"publish","type":"post","link":"https:\/\/blogs.ua.es\/ffic\/2013\/11\/18\/camp-electric-3\/","title":{"rendered":"Tema 4. Camp el\u00e8ctric (III)"},"content":{"rendered":"<p style=\"text-align: justify\">L&#8217;\u00faltima sessi\u00f3 d&#8217;aquest bloc se dedicar\u00e0 a l&#8217;estudi del <strong>corrent el\u00e8ctric<\/strong>, \u00e9s a dir, analitzar el moviment de les c\u00e0rregues dins d&#8217;un conductor a causa de l&#8217;exist\u00e8ncia d&#8217;un camp el\u00e8ctric. S&#8217;iniciar\u00e0 amb una descripci\u00f3 de la natura del corrent el\u00e8ctric i es definiran els conceptes d&#8217;<strong>intensitat de corrent el\u00e8ctrica<\/strong> i <strong>densitat de corrent<\/strong>. La intensitat de corrent es defineix com la c\u00e0rrega que travessa una superf\u00edcie per unitat de temps, i la densitat de corrent en un conductor com la intensitat per unitat de superf\u00edcie, que \u00e9s una magnitud vectorial la direcci\u00f3 de la qual \u00e9s la de la velocitat de les c\u00e0rregues.<\/p>\n<p style=\"text-align: justify\">Es continuar\u00e0 amb la deducci\u00f3 de la <strong>llei d&#8217;Ohm<\/strong> a partir de l&#8217;equaci\u00f3 general de la conducci\u00f3 el\u00e8ctrica i es definiran els conceptes de <strong>resist\u00e8ncia, resistivitat<\/strong> iy <strong>conductivitat<\/strong>. Tamb\u00e9 s&#8217;analitzaran les associacions de resist\u00e8ncies i la resist\u00e8ncia equivalent en cada cas. Es far\u00e0 una breu descripci\u00f3 d&#8217;instruments de mesura de magnituds el\u00e8ctriques.<\/p>\n<p style=\"text-align: justify\">En tot circuit el\u00e8ctric es produeix una p\u00e8rdua d&#8217;energia potencial, que \u00e9s la que guanya el conductor en forma de calor, la qual irradia a l&#8217;exterior, conegut com <strong>efecte Joule<\/strong>. Per tant, per a mantenir un circuit de corrent continu es necessiten dispositius que proporcionen energia el\u00e8ctrica a aquest. S&#8217;acabar\u00e0 la sessi\u00f3 amb l&#8217;estudi del <strong>circuits de corrent continu<\/strong> i obtindrem l&#8217;equaci\u00f3 de circuits senzills i la resoluci\u00f3 de circuits complicats mitjan\u00e7ant les <strong>regles de Kirchhoff<\/strong>, el <strong>m\u00e8tode de les corrents de malla<\/strong> i el <strong>teorema de Th\u00e9venin<\/strong>.<\/p>\n<p style=\"text-align: justify\">El Professor Walter Lewin del <strong>MIT<\/strong> (<a href=\"http:\/\/www.mit.edu\/\">Massachussetts Institute of Technology<\/a>) t\u00e9 un curs de f\u00edsica sencer enregistrat, l\u00f2gicament en angl\u00e9s, i podeu escoltar en el seg\u00fcent <a href=\"http:\/\/ocw.mit.edu\/courses\/physics\/8-02sc-physics-ii-electricity-and-magnetism-fall-2010\/circuits\/dc-circuits\/\">enlla\u00e7<\/a> la sessi\u00f3 corresponent a la resoluci\u00f3 de circuits de corrent continu mitjan\u00e7ant les regles de Kirchhoff.<\/p>\n<p style=\"text-align: justify\"><a href=\"http:\/\/ocw.mit.edu\/courses\/physics\/8-02sc-physics-ii-electricity-and-magnetism-fall-2010\/circuits\/dc-circuits\/\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-medium wp-image-406\" alt=\"ocw_mit\" src=\"https:\/\/blogs.ua.es\/ffic\/files\/2013\/11\/ocw_mit-300x36.png\" width=\"300\" height=\"36\" srcset=\"https:\/\/blogs.ua.es\/ffic\/files\/2013\/11\/ocw_mit-300x36.png 300w, https:\/\/blogs.ua.es\/ffic\/files\/2013\/11\/ocw_mit.png 374w\" sizes=\"auto, (max-width: 300px) 100vw, 300px\" \/><\/a>La sessi\u00f3 dedicada a circuits la podeu seguir en el v\u00eddeo seg\u00fcent.<\/p>\n<p style=\"text-align: justify\"><code>[kml_flashembed movie=\"http:\/\/www.youtube.com\/v\/RQX8I9ZWtPQ\" width=\"480\" height=\"360\" wmode=\"transparent\" \/]<\/code><\/p>\n","protected":false},"excerpt":{"rendered":"<p>L&#8217;\u00faltima sessi\u00f3 d&#8217;aquest bloc se dedicar\u00e0 a l&#8217;estudi del corrent el\u00e8ctric, \u00e9s a dir, analitzar el moviment de les c\u00e0rregues dins d&#8217;un conductor a causa de l&#8217;exist\u00e8ncia d&#8217;un camp el\u00e8ctric. S&#8217;iniciar\u00e0 amb una descripci\u00f3 de la natura del corrent el\u00e8ctric &hellip; <a href=\"https:\/\/blogs.ua.es\/ffic\/2013\/11\/18\/camp-electric-3\/\">Continue reading <span class=\"meta-nav\">&rarr;<\/span><\/a><\/p>\n","protected":false},"author":2285,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[9319,1366],"tags":[9330,1580705],"class_list":["post-397","post","type-post","status-publish","format-standard","hentry","category-asignatura-2","category-temas","tag-asignatura-3","tag-temas"],"_links":{"self":[{"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/posts\/397","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/users\/2285"}],"replies":[{"embeddable":true,"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/comments?post=397"}],"version-history":[{"count":11,"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/posts\/397\/revisions"}],"predecessor-version":[{"id":411,"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/posts\/397\/revisions\/411"}],"wp:attachment":[{"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/media?parent=397"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/categories?post=397"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blogs.ua.es\/ffic\/wp-json\/wp\/v2\/tags?post=397"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}