{"id":307346,"date":"2016-11-03T03:00:00","date_gmt":"2016-11-03T00:00:00","guid":{"rendered":"http:\/\/www.fyysika.ee\/?guid=6f28036f1ec146d81ef083ab230c5acd"},"modified":"2016-11-03T03:00:00","modified_gmt":"2016-11-03T00:00:00","slug":"an-elementary-argument-for-the-magnetic-field-outside-a-solenoid","status":"publish","type":"post","link":"https:\/\/www.fyysika.ee\/?p=307346","title":{"rendered":"An elementary argument for the magnetic field outside a solenoid"},"content":{"rendered":"<p>The evaluation of the magnetic field inside and outside a uniform current density infinite solenoid<br \/>\nof uniform cross-section is an elementary problem in classical electrodynamics that all<br \/>\nundergraduate Physics students study. Symmetry properties of the cylinder and the judicious use of<br \/>\nAmpere\u2019s circuital law leads to correct results; however it does not explain why the field is non<br \/>\nzero for a finite length solenoid, and why it vanishes as the solenoid becomes infinitely long. An<br \/>\nargument is provided in Farley and Price (2001 Am. J. Phys. 69 [http:\/\/dx.doi.org\/10.1119\/1.1362694]<br \/>\n751 ), explaining how the magnetic field behaves outside the solenoid and not too far from it, as a<br \/>\nfunction of the length of the solenoid. A calculation is also outlined for obtaining the field just<br \/>\noutside the circular cross section solenoid, in the classic text Classical Electrodynamics by<br \/>\nJackson, 3rd edn (John Wiley and Sons, Inc.), problems 5.3\u20135.5. The purpose of th&#8230;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>The evaluation of the magnetic field inside and outside a uniform current density infinite solenoid<br \/>\nof uniform cross-section is an elementary problem in classical electrodynamics that all<br \/>\nundergraduate Physics students study. Symmetry properties of t&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","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":[178],"tags":[],"class_list":{"0":"post-307346","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-rss-fuusikaharidus","7":"entry"},"_links":{"self":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/307346","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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=307346"}],"version-history":[{"count":0,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=\/wp\/v2\/posts\/307346\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=307346"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=307346"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.fyysika.ee\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=307346"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}