{"id":85233,"date":"2025-06-01T03:08:33","date_gmt":"2025-06-01T03:08:33","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=85233"},"modified":"2025-06-01T03:08:33","modified_gmt":"2025-06-01T03:08:33","slug":"the-twinkling-of-a-star-is-due-to","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/the-twinkling-of-a-star-is-due-to\/","title":{"rendered":"The twinkling of a star is due to :"},"content":{"rendered":"<p>The twinkling of a star is due to :<\/p>\n<p>[amp_mcq option1=&#8221;atmospheric reflection of starlight.&#8221; option2=&#8221;atmospheric refraction of starlight.&#8221; option3=&#8221;continuous change in the position of the star.&#8221; option4=&#8221;oscillation of starlight.&#8221; correct=&#8221;option2&#8243;]<\/p>\n<div class=\"psc-box-pyq-exam-year-detail\">\n<div class=\"pyq-exam\">\n<div class=\"psc-heading\">This question was previously asked in<\/div>\n<div class=\"psc-title line-ellipsis\">UPSC CDS-1 &#8211; 2022<\/div>\n<\/div>\n<div class=\"pyq-exam-psc-buttons\"><a href=\"\/pyq\/pyq-upsc-cds-1-2022.pdf\" target=\"_blank\" class=\"psc-pdf-button\" rel=\"noopener\">Download PDF<\/a><a href=\"\/pyq-upsc-cds-1-2022\" target=\"_blank\" class=\"psc-attempt-button\" rel=\"noopener\">Attempt Online<\/a><\/div>\n<\/div>\n<section id=\"pyq-correct-answer\">\nThe twinkling of a star is due to atmospheric refraction of starlight.<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\nStarlight travels through the Earth&#8217;s atmosphere before reaching our eyes. The atmosphere is composed of layers with different densities and temperatures, causing the refractive index to vary continuously. As starlight passes through these varying layers, it is refracted or bent slightly in different directions. This continuous change in the path of light causes fluctuations in the apparent brightness and position of the star, leading to the twinkling effect.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nPlanets, being much closer, appear as discs rather than point sources of light. Although their light is also refracted, the light from different parts of the disc averages out the effect, which is why planets do not typically twinkle as much as stars. Reflection (bouncing light off a surface) is not the cause of twinkling.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>The twinkling of a star is due to : [amp_mcq option1=&#8221;atmospheric reflection of starlight.&#8221; option2=&#8221;atmospheric refraction of starlight.&#8221; option3=&#8221;continuous change in the position of the star.&#8221; option4=&#8221;oscillation of starlight.&#8221; correct=&#8221;option2&#8243;] This question was previously asked in UPSC CDS-1 &#8211; 2022 Download PDFAttempt Online The twinkling of a star is due to atmospheric refraction of starlight. &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"The twinkling of a star is due to :\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/the-twinkling-of-a-star-is-due-to\/#more-85233\">Detailed Solution<span class=\"screen-reader-text\">The twinkling of a star is due to :<\/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":[1087],"tags":[1108,1153,1128],"class_list":["post-85233","post","type-post","status-publish","format-standard","hentry","category-upsc-cds-1","tag-1108","tag-optics","tag-physics","no-featured-image-padding"],"yoast_head":"<!-- This site is optimized with the Yoast SEO Premium plugin v22.2 (Yoast SEO v23.3) - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>The twinkling of a star is due to :<\/title>\n<meta name=\"description\" content=\"The twinkling of a star is due to atmospheric refraction of starlight. Starlight travels through the Earth&#039;s atmosphere before reaching our eyes. The atmosphere is composed of layers with different densities and temperatures, causing the refractive index to vary continuously. As starlight passes through these varying layers, it is refracted or bent slightly in different directions. This continuous change in the path of light causes fluctuations in the apparent brightness and position of the star, leading to the twinkling effect.\" \/>\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\/the-twinkling-of-a-star-is-due-to\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The twinkling of a star is due to :\" \/>\n<meta property=\"og:description\" content=\"The twinkling of a star is due to atmospheric refraction of starlight. Starlight travels through the Earth&#039;s atmosphere before reaching our eyes. The atmosphere is composed of layers with different densities and temperatures, causing the refractive index to vary continuously. As starlight passes through these varying layers, it is refracted or bent slightly in different directions. This continuous change in the path of light causes fluctuations in the apparent brightness and position of the star, leading to the twinkling effect.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/the-twinkling-of-a-star-is-due-to\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T03:08:33+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":"The twinkling of a star is due to :","description":"The twinkling of a star is due to atmospheric refraction of starlight. Starlight travels through the Earth's atmosphere before reaching our eyes. The atmosphere is composed of layers with different densities and temperatures, causing the refractive index to vary continuously. As starlight passes through these varying layers, it is refracted or bent slightly in different directions. This continuous change in the path of light causes fluctuations in the apparent brightness and position of the star, leading to the twinkling effect.","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\/the-twinkling-of-a-star-is-due-to\/","og_locale":"en_US","og_type":"article","og_title":"The twinkling of a star is due to :","og_description":"The twinkling of a star is due to atmospheric refraction of starlight. Starlight travels through the Earth's atmosphere before reaching our eyes. The atmosphere is composed of layers with different densities and temperatures, causing the refractive index to vary continuously. As starlight passes through these varying layers, it is refracted or bent slightly in different directions. This continuous change in the path of light causes fluctuations in the apparent brightness and position of the star, leading to the twinkling effect.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/the-twinkling-of-a-star-is-due-to\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T03:08:33+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\/the-twinkling-of-a-star-is-due-to\/","url":"https:\/\/exam.pscnotes.com\/mcq\/the-twinkling-of-a-star-is-due-to\/","name":"The twinkling of a star is due to :","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T03:08:33+00:00","dateModified":"2025-06-01T03:08:33+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"The twinkling of a star is due to atmospheric refraction of starlight. Starlight travels through the Earth's atmosphere before reaching our eyes. The atmosphere is composed of layers with different densities and temperatures, causing the refractive index to vary continuously. As starlight passes through these varying layers, it is refracted or bent slightly in different directions. This continuous change in the path of light causes fluctuations in the apparent brightness and position of the star, leading to the twinkling effect.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/the-twinkling-of-a-star-is-due-to\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/the-twinkling-of-a-star-is-due-to\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/the-twinkling-of-a-star-is-due-to\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CDS-1","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-cds-1\/"},{"@type":"ListItem","position":3,"name":"The twinkling of a star is due to :"}]},{"@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\/85233","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=85233"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/85233\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=85233"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=85233"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=85233"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}