{"id":86725,"date":"2025-06-01T04:19:30","date_gmt":"2025-06-01T04:19:30","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=86725"},"modified":"2025-06-01T04:19:30","modified_gmt":"2025-06-01T04:19:30","slug":"a-straight-conducting-wire-carries-a-dc-current-through-it-which-one","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/a-straight-conducting-wire-carries-a-dc-current-through-it-which-one\/","title":{"rendered":"A straight conducting wire carries a DC current through it. Which one"},"content":{"rendered":"

A straight conducting wire carries a DC current through it. Which one of the following statements is true regarding the magnetic field around the wire?<\/p>\n

[amp_mcq option1=”The magnetic field does not depend upon the amount of current flowing through the wire” option2=”The magnetic field does not depend upon the distance from the wire” option3=”The magnetic field depends upon the material of the wire” option4=”The magnetic field decreases with an increase from the wire” correct=”option4″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC Geoscientist – 2020<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nThe magnetic field around a straight conducting wire carrying a DC current decreases with an increase in distance from the wire.
\n<\/section>\n
\nThe magnitude of the magnetic field (B) at a distance ‘r’ from a long, straight wire carrying a current ‘I’ is given by the formula $B = \\frac{\\mu_0 I}{2\\pi r}$ (in vacuum or air). This formula shows that B is directly proportional to the current I and inversely proportional to the distance r.
\n<\/section>\n
\nAccording to the formula, the magnetic field strength decreases as the distance from the wire increases (option D). The magnetic field strength depends on the current flowing through the wire (option A is false). The magnetic field strength depends on the distance from the wire (option B is false). The formula contains $\\mu_0$, the permeability of free space, which is a property of the medium, not the wire material itself (assuming the wire is non-magnetic and the medium is uniform) (option C is false). The direction of the magnetic field lines around the wire is circular, concentric with the wire, and can be determined by the right-hand rule.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

A straight conducting wire carries a DC current through it. Which one of the following statements is true regarding the magnetic field around the wire? [amp_mcq option1=”The magnetic field does not depend upon the amount of current flowing through the wire” option2=”The magnetic field does not depend upon the distance from the wire” option3=”The magnetic … <\/p>\n

Detailed SolutionA straight conducting wire carries a DC current through it. Which one<\/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":[1091],"tags":[1288,1201,1128],"class_list":["post-86725","post","type-post","status-publish","format-standard","hentry","category-upsc-geoscientist","tag-1288","tag-electric-current","tag-physics","no-featured-image-padding"],"yoast_head":"\nA straight conducting wire carries a DC current through it. Which one<\/title>\n<meta name=\"description\" content=\"The magnetic field around a straight conducting wire carrying a DC current decreases with an increase in distance from the wire. The magnitude of the magnetic field (B) at a distance 'r' from a long, straight wire carrying a current 'I' is given by the formula $B = frac{mu_0 I}{2pi r}$ (in vacuum or air). This formula shows that B is directly proportional to the current I and inversely proportional to the distance r.\" \/>\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\/a-straight-conducting-wire-carries-a-dc-current-through-it-which-one\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"A straight conducting wire carries a DC current through it. Which one\" \/>\n<meta property=\"og:description\" content=\"The magnetic field around a straight conducting wire carrying a DC current decreases with an increase in distance from the wire. The magnitude of the magnetic field (B) at a distance 'r' from a long, straight wire carrying a current 'I' is given by the formula $B = frac{mu_0 I}{2pi r}$ (in vacuum or air). 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