{"id":87474,"date":"2025-06-01T06:44:53","date_gmt":"2025-06-01T06:44:53","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=87474"},"modified":"2025-06-01T06:44:53","modified_gmt":"2025-06-01T06:44:53","slug":"in-a-solenoid-the-current-flowing-through-the-wire-is-i-and-number-of","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/in-a-solenoid-the-current-flowing-through-the-wire-is-i-and-number-of\/","title":{"rendered":"In a solenoid, the current flowing through the wire is I and number of"},"content":{"rendered":"

In a solenoid, the current flowing through the wire is I and number of turns per unit length is n. This gives a magnetic field B inside the solenoid. If number of turn per unit length is increased to 2n, what will be the value of magnetic field in the solenoid?<\/p>\n

[amp_mcq option1=”B” option2=”2B” option3=”B\/2″ option4=”B\/4″ correct=”option2″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC NDA-1 – 2017<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nThe correct answer is 2B. The magnetic field inside a long solenoid is directly proportional to the number of turns per unit length and the current flowing through the wire.
\n<\/section>\n
\nThe formula for the magnetic field inside an ideal long solenoid is B = \u03bc\u2080 * n * I, where \u03bc\u2080 is the permeability of free space, n is the number of turns per unit length, and I is the current. If the number of turns per unit length is increased to 2n while the current I remains the same, the new magnetic field B’ will be B’ = \u03bc\u2080 * (2n) * I = 2 * (\u03bc\u2080 * n * I).
\n<\/section>\n
\nSince the original magnetic field was B = \u03bc\u2080 * n * I, the new magnetic field is B’ = 2B. The magnetic field strength inside a solenoid can be increased by increasing the current, increasing the number of turns per unit length, or by inserting a core material with a higher permeability (like iron) into the solenoid.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

In a solenoid, the current flowing through the wire is I and number of turns per unit length is n. This gives a magnetic field B inside the solenoid. If number of turn per unit length is increased to 2n, what will be the value of magnetic field in the solenoid? [amp_mcq option1=”B” option2=”2B” option3=”B\/2″ … <\/p>\n

Detailed SolutionIn a solenoid, the current flowing through the wire is I and number of<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1093],"tags":[1101,1201,1128],"class_list":["post-87474","post","type-post","status-publish","format-standard","hentry","category-upsc-nda-1","tag-1101","tag-electric-current","tag-physics","no-featured-image-padding"],"yoast_head":"\nIn a solenoid, the current flowing through the wire is I and number of<\/title>\n<meta name=\"description\" content=\"The correct answer is 2B. The magnetic field inside a long solenoid is directly proportional to the number of turns per unit length and the current flowing through the wire. The formula for the magnetic field inside an ideal long solenoid is B = \u03bc\u2080 * n * I, where \u03bc\u2080 is the permeability of free space, n is the number of turns per unit length, and I is the current. If the number of turns per unit length is increased to 2n while the current I remains the same, the new magnetic field B' will be B' = \u03bc\u2080 * (2n) * I = 2 * (\u03bc\u2080 * n * I).\" \/>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/exam.pscnotes.com\/mcq\/in-a-solenoid-the-current-flowing-through-the-wire-is-i-and-number-of\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"In a solenoid, the current flowing through the wire is I and number of\" \/>\n<meta property=\"og:description\" content=\"The correct answer is 2B. The magnetic field inside a long solenoid is directly proportional to the number of turns per unit length and the current flowing through the wire. The formula for the magnetic field inside an ideal long solenoid is B = \u03bc\u2080 * n * I, where \u03bc\u2080 is the permeability of free space, n is the number of turns per unit length, and I is the current. If the number of turns per unit length is increased to 2n while the current I remains the same, the new magnetic field B' will be B' = \u03bc\u2080 * (2n) * I = 2 * (\u03bc\u2080 * n * I).\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/in-a-solenoid-the-current-flowing-through-the-wire-is-i-and-number-of\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T06:44:53+00:00\" \/>\n<meta name=\"author\" content=\"rawan239\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"Written by\" \/>\n\t<meta name=\"twitter:data1\" content=\"rawan239\" \/>\n\t<meta name=\"twitter:label2\" content=\"Est. reading time\" \/>\n\t<meta name=\"twitter:data2\" content=\"1 minute\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"In a solenoid, the current flowing through the wire is I and number of","description":"The correct answer is 2B. The magnetic field inside a long solenoid is directly proportional to the number of turns per unit length and the current flowing through the wire. The formula for the magnetic field inside an ideal long solenoid is B = \u03bc\u2080 * n * I, where \u03bc\u2080 is the permeability of free space, n is the number of turns per unit length, and I is the current. If the number of turns per unit length is increased to 2n while the current I remains the same, the new magnetic field B' will be B' = \u03bc\u2080 * (2n) * I = 2 * (\u03bc\u2080 * n * I).","robots":{"index":"index","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"canonical":"https:\/\/exam.pscnotes.com\/mcq\/in-a-solenoid-the-current-flowing-through-the-wire-is-i-and-number-of\/","og_locale":"en_US","og_type":"article","og_title":"In a solenoid, the current flowing through the wire is I and number of","og_description":"The correct answer is 2B. The magnetic field inside a long solenoid is directly proportional to the number of turns per unit length and the current flowing through the wire. The formula for the magnetic field inside an ideal long solenoid is B = \u03bc\u2080 * n * I, where \u03bc\u2080 is the permeability of free space, n is the number of turns per unit length, and I is the current. If the number of turns per unit length is increased to 2n while the current I remains the same, the new magnetic field B' will be B' = \u03bc\u2080 * (2n) * I = 2 * (\u03bc\u2080 * n * I).","og_url":"https:\/\/exam.pscnotes.com\/mcq\/in-a-solenoid-the-current-flowing-through-the-wire-is-i-and-number-of\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T06:44:53+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"1 minute"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/in-a-solenoid-the-current-flowing-through-the-wire-is-i-and-number-of\/","url":"https:\/\/exam.pscnotes.com\/mcq\/in-a-solenoid-the-current-flowing-through-the-wire-is-i-and-number-of\/","name":"In a solenoid, the current flowing through the wire is I and number of","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T06:44:53+00:00","dateModified":"2025-06-01T06:44:53+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The correct answer is 2B. The magnetic field inside a long solenoid is directly proportional to the number of turns per unit length and the current flowing through the wire. The formula for the magnetic field inside an ideal long solenoid is B = \u03bc\u2080 * n * I, where \u03bc\u2080 is the permeability of free space, n is the number of turns per unit length, and I is the current. 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