{"id":149343,"date":"2024-03-04T19:33:10","date_gmt":"2024-03-04T14:03:10","guid":{"rendered":"https:\/\/www.mapsofindia.com\/my-india\/?p=149343"},"modified":"2024-03-04T19:33:10","modified_gmt":"2024-03-04T14:03:10","slug":"an-electron-is-revolving-around-a-proton-in-an-orbit-of-radius-r-with-a","status":"publish","type":"post","link":"https:\/\/www.mapsofindia.com\/my-india\/quiz\/an-electron-is-revolving-around-a-proton-in-an-orbit-of-radius-r-with-a","title":{"rendered":"An electron is revolving around a proton in an orbit of radius r with a&#8230;"},"content":{"rendered":"<h2>An electron is revolving around a proton in an orbit of radius r with a speed v. Obtain expression for magnetic moment associated with the electron.<\/h2>\n<h3>Ans. The magnetic moment associated with the electron in its orbit around the proton can be calculated using the formula for the magnetic moment of a current loop.<\/h3>\n<h3>The current in the loop is due to the moving electron. The current, <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">I<\/span><\/span><\/span><\/span><\/span>, is the charge <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">q<\/span><\/span><\/span><\/span><\/span> of the electron moving in a circle of radius <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">r<\/span><\/span><\/span><\/span><\/span> with velocity <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">v<\/span><\/span><\/span><\/span><\/span>. So, we have:<\/h3>\n<h3><span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd=\ufffd\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">I<\/span><span class=\"mrel\">=<\/span><\/span><span class=\"base\"><span class=\"mord\"><span class=\"mfrac\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\"><span class=\"mord mathnormal mtight\">T<\/span><\/span><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\"><span class=\"mord mathnormal mtight\">q<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/h3>\n<h3>Where <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">T<\/span><\/span><\/span><\/span><\/span> is the time period of the orbit.<\/h3>\n<h3>The time period of the orbit is the time taken by the electron to complete one revolution around the proton, which can be given by:<\/h3>\n<h3><span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd=2\ufffd\ufffd\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">T<\/span><span class=\"mrel\">=<\/span><\/span><span class=\"base\"><span class=\"mord\"><span class=\"mfrac\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\"><span class=\"mord mathnormal mtight\">v<\/span><\/span><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">2<span class=\"mord mathnormal mtight\">\u03c0<\/span><span class=\"mord mathnormal mtight\">r<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/h3>\n<h3>Now, substituting <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">T<\/span><\/span><\/span><\/span><\/span> in the expression for <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">I<\/span><\/span><\/span><\/span><\/span>, we get:<\/h3>\n<h3><span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd=\ufffd2\ufffd\ufffd\ufffd=\ufffd\ufffd2\ufffd\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">I<\/span><span class=\"mrel\">=<\/span><\/span><span class=\"base\"><span class=\"mord\"><span class=\"mfrac\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\"><span class=\"sizing reset-size3 size1 mtight\"><span class=\"mord mathnormal mtight\">v<\/span><\/span><span class=\"sizing reset-size3 size1 mtight\">2<span class=\"mord mathnormal mtight\">\u03c0<\/span><span class=\"mord mathnormal mtight\">r<\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\"><span class=\"mord mathnormal mtight\">q<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><\/span><\/span><\/span><span class=\"mrel\">=<\/span><\/span><span class=\"base\"><span class=\"mord\"><span class=\"mfrac\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">2<span class=\"mord mathnormal mtight\">\u03c0<\/span><span class=\"mord mathnormal mtight\">r<\/span><\/span><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\"><span class=\"mord mathnormal mtight\">q<\/span><span class=\"mord mathnormal mtight\">v<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/h3>\n<h3>The magnetic moment <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">\u03bc<\/span><\/span><\/span><\/span><\/span> of the current loop is given by the product of the current <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">I<\/span><\/span><\/span><\/span><\/span> and the area <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">A<\/span><\/span><\/span><\/span><\/span> of the loop, which is equal to <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd\ufffd2<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">\u03c0<\/span><span class=\"mord\"><span class=\"mord mathnormal\">r<\/span><span class=\"msupsub\"><span class=\"vlist-t\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">2<\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span><\/span>:<\/h3>\n<h3><span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd=\ufffd\u22c5\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">\u03bc<\/span><span class=\"mrel\">=<\/span><\/span><span class=\"base\"><span class=\"mord mathnormal\">I<\/span><span class=\"mbin\">\u22c5<\/span><\/span><span class=\"base\"><span class=\"mord mathnormal\">A<\/span><\/span><\/span><\/span><\/span><\/h3>\n<h3><span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">\ufffd=\ufffd\ufffd2\ufffd\ufffd\u22c5\ufffd\ufffd2=12\ufffd\ufffd\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord mathnormal\">\u03bc<\/span><span class=\"mrel\">=<\/span><\/span><span class=\"base\"><span class=\"mord\"><span class=\"mfrac\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">2<span class=\"mord mathnormal mtight\">\u03c0<\/span><span class=\"mord mathnormal mtight\">r<\/span><\/span><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\"><span class=\"mord mathnormal mtight\">q<\/span><span class=\"mord mathnormal mtight\">v<\/span><\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><\/span><\/span><\/span><span class=\"mbin\">\u22c5<\/span><\/span><span class=\"base\"><span class=\"mord mathnormal\">\u03c0<\/span><span class=\"mord\"><span class=\"mord mathnormal\">r<\/span><span class=\"msupsub\"><span class=\"vlist-t\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">2<\/span><\/span><\/span><\/span><\/span><\/span><\/span><span class=\"mrel\">=<\/span><\/span><span class=\"base\"><span class=\"mord\"><span class=\"mfrac\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">2<\/span><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">1<\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><\/span><\/span><\/span><span class=\"mord mathnormal\">q<\/span><span class=\"mord mathnormal\">v<\/span><span class=\"mord mathnormal\">r<\/span><\/span><\/span><\/span><\/span><\/h3>\n<h3>So, the expression for the magnetic moment associated with the electron is <span class=\"math math-inline\"><span class=\"katex\"><span class=\"katex-mathml\">12\ufffd\ufffd\ufffd<\/span><span class=\"katex-html\" aria-hidden=\"true\"><span class=\"base\"><span class=\"mord\"><span class=\"mfrac\"><span class=\"vlist-t vlist-t2\"><span class=\"vlist-r\"><span class=\"vlist\"><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">2<\/span><\/span><span class=\"sizing reset-size6 size3 mtight\"><span class=\"mord mtight\">1<\/span><\/span><\/span><span class=\"vlist-s\">\u200b<\/span><\/span><\/span><\/span><\/span><span class=\"mord mathnormal\">q<\/span><span class=\"mord mathnormal\">v<\/span><span class=\"mord mathnormal\">r<\/span><\/span><\/span><\/span><\/span>.<\/h3>\n","protected":false},"excerpt":{"rendered":"<p>An electron is revolving around a proton in an orbit of radius r with a speed v. Obtain expression for magnetic moment associated with the electron. Ans. The magnetic moment associated with the electron in its orbit around the proton can be calculated using the formula for the magnetic moment of a current loop. The [&hellip;]<\/p>\n","protected":false},"author":21830,"featured_media":114041,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[12119],"tags":[],"class_list":{"0":"post-149343","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-quiz"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/posts\/149343","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/users\/21830"}],"replies":[{"embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/comments?post=149343"}],"version-history":[{"count":1,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/posts\/149343\/revisions"}],"predecessor-version":[{"id":149344,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/posts\/149343\/revisions\/149344"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/media\/114041"}],"wp:attachment":[{"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/media?parent=149343"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/categories?post=149343"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.mapsofindia.com\/my-india\/wp-json\/wp\/v2\/tags?post=149343"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}