{"id":86946,"date":"2025-06-01T04:24:07","date_gmt":"2025-06-01T04:24:07","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=86946"},"modified":"2025-06-01T04:24:07","modified_gmt":"2025-06-01T04:24:07","slug":"which-two-competing-effects-determine-the-size-of-a-star","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/which-two-competing-effects-determine-the-size-of-a-star\/","title":{"rendered":"Which two competing effects determine the size of a star?"},"content":{"rendered":"

Which two competing effects determine the size of a star?<\/p>\n

[amp_mcq option1=”Nuclear fusion and electrostatic effects” option2=”Nuclear fusion and magnetic effects” option3=”Nuclear fusion and gravitational effects” option4=”Gravitational and electromagnetic effects” correct=”option3″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC Geoscientist – 2022<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nThe size of a stable star is determined by the balance between the inward force of gravity and the outward pressure generated by nuclear fusion in its core.
\n<\/section>\n
\nGravity constantly pulls the star’s mass inward, tending to collapse it. Nuclear fusion reactions in the core, primarily converting hydrogen to helium, release enormous amounts of energy in the form of photons (radiation) and particles. This energy creates a strong outward pressure (radiation pressure and thermal pressure) that counteracts gravity. A star remains stable, maintaining a relatively constant size, when these two opposing forces are in equilibrium, known as hydrostatic equilibrium.
\n<\/section>\n
\nWhile other effects like magnetic fields can influence stellar activity and structure in specific regions or phases, the primary factors determining the overall size and stability of a star throughout its main sequence life are the balance between self-gravity and the pressure from nuclear fusion.
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

Which two competing effects determine the size of a star? [amp_mcq option1=”Nuclear fusion and electrostatic effects” option2=”Nuclear fusion and magnetic effects” option3=”Nuclear fusion and gravitational effects” option4=”Gravitational and electromagnetic effects” correct=”option3″] This question was previously asked in UPSC Geoscientist – 2022 Download PDFAttempt Online The size of a stable star is determined by the balance … <\/p>\n

Detailed SolutionWhich two competing effects determine the size of a star?<\/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":[1108,1128,1435],"class_list":["post-86946","post","type-post","status-publish","format-standard","hentry","category-upsc-geoscientist","tag-1108","tag-physics","tag-space","no-featured-image-padding"],"yoast_head":"\nWhich two competing effects determine the size of a star?<\/title>\n<meta name=\"description\" content=\"The size of a stable star is determined by the balance between the inward force of gravity and the outward pressure generated by nuclear fusion in its core. Gravity constantly pulls the star's mass inward, tending to collapse it. Nuclear fusion reactions in the core, primarily converting hydrogen to helium, release enormous amounts of energy in the form of photons (radiation) and particles. This energy creates a strong outward pressure (radiation pressure and thermal pressure) that counteracts gravity. A star remains stable, maintaining a relatively constant size, when these two opposing forces are in equilibrium, known as hydrostatic equilibrium.\" \/>\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\/which-two-competing-effects-determine-the-size-of-a-star\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Which two competing effects determine the size of a star?\" \/>\n<meta property=\"og:description\" content=\"The size of a stable star is determined by the balance between the inward force of gravity and the outward pressure generated by nuclear fusion in its core. Gravity constantly pulls the star's mass inward, tending to collapse it. Nuclear fusion reactions in the core, primarily converting hydrogen to helium, release enormous amounts of energy in the form of photons (radiation) and particles. This energy creates a strong outward pressure (radiation pressure and thermal pressure) that counteracts gravity. A star remains stable, maintaining a relatively constant size, when these two opposing forces are in equilibrium, known as hydrostatic equilibrium.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/which-two-competing-effects-determine-the-size-of-a-star\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T04:24:07+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":"Which two competing effects determine the size of a star?","description":"The size of a stable star is determined by the balance between the inward force of gravity and the outward pressure generated by nuclear fusion in its core. Gravity constantly pulls the star's mass inward, tending to collapse it. Nuclear fusion reactions in the core, primarily converting hydrogen to helium, release enormous amounts of energy in the form of photons (radiation) and particles. This energy creates a strong outward pressure (radiation pressure and thermal pressure) that counteracts gravity. A star remains stable, maintaining a relatively constant size, when these two opposing forces are in equilibrium, known as hydrostatic equilibrium.","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\/which-two-competing-effects-determine-the-size-of-a-star\/","og_locale":"en_US","og_type":"article","og_title":"Which two competing effects determine the size of a star?","og_description":"The size of a stable star is determined by the balance between the inward force of gravity and the outward pressure generated by nuclear fusion in its core. Gravity constantly pulls the star's mass inward, tending to collapse it. Nuclear fusion reactions in the core, primarily converting hydrogen to helium, release enormous amounts of energy in the form of photons (radiation) and particles. This energy creates a strong outward pressure (radiation pressure and thermal pressure) that counteracts gravity. A star remains stable, maintaining a relatively constant size, when these two opposing forces are in equilibrium, known as hydrostatic equilibrium.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/which-two-competing-effects-determine-the-size-of-a-star\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T04:24:07+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\/which-two-competing-effects-determine-the-size-of-a-star\/","url":"https:\/\/exam.pscnotes.com\/mcq\/which-two-competing-effects-determine-the-size-of-a-star\/","name":"Which two competing effects determine the size of a star?","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T04:24:07+00:00","dateModified":"2025-06-01T04:24:07+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The size of a stable star is determined by the balance between the inward force of gravity and the outward pressure generated by nuclear fusion in its core. Gravity constantly pulls the star's mass inward, tending to collapse it. Nuclear fusion reactions in the core, primarily converting hydrogen to helium, release enormous amounts of energy in the form of photons (radiation) and particles. This energy creates a strong outward pressure (radiation pressure and thermal pressure) that counteracts gravity. A star remains stable, maintaining a relatively constant size, when these two opposing forces are in equilibrium, known as hydrostatic equilibrium.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/which-two-competing-effects-determine-the-size-of-a-star\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/which-two-competing-effects-determine-the-size-of-a-star\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-two-competing-effects-determine-the-size-of-a-star\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC Geoscientist","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-geoscientist\/"},{"@type":"ListItem","position":3,"name":"Which two competing effects determine the size of a star?"}]},{"@type":"WebSite","@id":"https:\/\/exam.pscnotes.com\/mcq\/#website","url":"https:\/\/exam.pscnotes.com\/mcq\/","name":"MCQ and Quiz for Exams","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/exam.pscnotes.com\/mcq\/?s={search_term_string}"},"query-input":"required name=search_term_string"}],"inLanguage":"en-US"},{"@type":"Person","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209","name":"rawan239","image":{"@type":"ImageObject","inLanguage":"en-US","@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/image\/","url":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/761a7274f9cce048fa5b921221e7934820d74514df93ef195a9d22af0c1c9001?s=96&d=mm&r=g","caption":"rawan239"},"sameAs":["https:\/\/exam.pscnotes.com"],"url":"https:\/\/exam.pscnotes.com\/mcq\/author\/rawan239\/"}]}},"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/86946","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/comments?post=86946"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/86946\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=86946"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=86946"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=86946"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}