{"id":87373,"date":"2025-06-01T06:41:55","date_gmt":"2025-06-01T06:41:55","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=87373"},"modified":"2025-06-01T06:41:55","modified_gmt":"2025-06-01T06:41:55","slug":"the-brightness-of-a-star-depends-on-its","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/the-brightness-of-a-star-depends-on-its\/","title":{"rendered":"The brightness of a star depends on its"},"content":{"rendered":"

The brightness of a star depends on its<\/p>\n

[amp_mcq option1=”size and temperature only” option2=”size and distance from the earth” option3=”size, temperature and mass” option4=”size, temperature and distance from the earth” correct=”option4″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC NDA-1 – 2016<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nThe correct option is D.
\n<\/section>\n
\nThe apparent brightness of a star as observed from Earth depends on two primary factors: its intrinsic luminosity and its distance from the observer. The intrinsic luminosity of a star, which is the total energy it radiates per unit time, is determined by its size (radius) and its surface temperature. Larger and hotter stars are more luminous. Therefore, the brightness we perceive (apparent brightness) is a function of the star’s size, temperature (which together determine luminosity), and the distance the light travels to reach us. The inverse square law dictates that brightness decreases with the square of the distance.
\n<\/section>\n
\nWhile mass is a fundamental property of a star and influences its temperature, size, and lifespan, the most direct factors determining luminosity are size and temperature. Apparent magnitude is a measure of apparent brightness, while absolute magnitude measures intrinsic luminosity (brightness at a standard distance of 10 parsecs).
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

The brightness of a star depends on its [amp_mcq option1=”size and temperature only” option2=”size and distance from the earth” option3=”size, temperature and mass” option4=”size, temperature and distance from the earth” correct=”option4″] This question was previously asked in UPSC NDA-1 – 2016 Download PDFAttempt Online The correct option is D. The apparent brightness of a star … <\/p>\n

Detailed SolutionThe brightness of a star depends on its<\/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":[1098,1128,1435],"class_list":["post-87373","post","type-post","status-publish","format-standard","hentry","category-upsc-nda-1","tag-1098","tag-physics","tag-space","no-featured-image-padding"],"yoast_head":"\nThe brightness of a star depends on its<\/title>\n<meta name=\"description\" content=\"The correct option is D. The apparent brightness of a star as observed from Earth depends on two primary factors: its intrinsic luminosity and its distance from the observer. The intrinsic luminosity of a star, which is the total energy it radiates per unit time, is determined by its size (radius) and its surface temperature. Larger and hotter stars are more luminous. Therefore, the brightness we perceive (apparent brightness) is a function of the star's size, temperature (which together determine luminosity), and the distance the light travels to reach us. The inverse square law dictates that brightness decreases with the square of the distance.\" \/>\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-brightness-of-a-star-depends-on-its\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"The brightness of a star depends on its\" \/>\n<meta property=\"og:description\" content=\"The correct option is D. The apparent brightness of a star as observed from Earth depends on two primary factors: its intrinsic luminosity and its distance from the observer. The intrinsic luminosity of a star, which is the total energy it radiates per unit time, is determined by its size (radius) and its surface temperature. Larger and hotter stars are more luminous. Therefore, the brightness we perceive (apparent brightness) is a function of the star's size, temperature (which together determine luminosity), and the distance the light travels to reach us. The inverse square law dictates that brightness decreases with the square of the distance.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/the-brightness-of-a-star-depends-on-its\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T06:41:55+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 brightness of a star depends on its","description":"The correct option is D. 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The inverse square law dictates that brightness decreases with the square of the distance.","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-brightness-of-a-star-depends-on-its\/","og_locale":"en_US","og_type":"article","og_title":"The brightness of a star depends on its","og_description":"The correct option is D. The apparent brightness of a star as observed from Earth depends on two primary factors: its intrinsic luminosity and its distance from the observer. The intrinsic luminosity of a star, which is the total energy it radiates per unit time, is determined by its size (radius) and its surface temperature. Larger and hotter stars are more luminous. 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The apparent brightness of a star as observed from Earth depends on two primary factors: its intrinsic luminosity and its distance from the observer. The intrinsic luminosity of a star, which is the total energy it radiates per unit time, is determined by its size (radius) and its surface temperature. Larger and hotter stars are more luminous. Therefore, the brightness we perceive (apparent brightness) is a function of the star's size, temperature (which together determine luminosity), and the distance the light travels to reach us. 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