{"id":88388,"date":"2025-06-01T07:09:20","date_gmt":"2025-06-01T07:09:20","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=88388"},"modified":"2025-06-01T07:09:20","modified_gmt":"2025-06-01T07:09:20","slug":"light-year-is-a-measure-of","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/light-year-is-a-measure-of\/","title":{"rendered":"Light year is a measure of"},"content":{"rendered":"

Light year is a measure of<\/p>\n

[amp_mcq option1=”time” option2=”distance” option3=”total amount of light falling on the Earth in a year” option4=”average intensity of light falling on the Earth in a year” correct=”option2″]<\/p>\n

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\n
This question was previously asked in<\/div>\n
UPSC NDA-2 – 2017<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nA light-year is defined as the distance that light travels in vacuum in one Julian year (365.25 days). Because light travels at a finite, constant speed in vacuum, the distance it covers over a fixed period of time is a specific value. Therefore, a light-year is a unit used to measure distances, particularly in astronomy, for vast interstellar and intergalactic scales.
\n<\/section>\n
\n– A light-year is the distance light travels in one year.
\n– It is a unit of distance.
\n– Used for measuring large distances in astronomy.
\n<\/section>\n
\nThe speed of light in vacuum is approximately 299,792,458 meters per second. One light-year is approximately 9.461 trillion kilometers (9.461 \u00d7 10\u00b9\u00b2 km) or 5.879 trillion miles (5.879 \u00d7 10\u00b9\u00b2 miles). Other units of astronomical distance include the astronomical unit (AU) and the parsec (pc).
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

Light year is a measure of [amp_mcq option1=”time” option2=”distance” option3=”total amount of light falling on the Earth in a year” option4=”average intensity of light falling on the Earth in a year” correct=”option2″] This question was previously asked in UPSC NDA-2 – 2017 Download PDFAttempt Online A light-year is defined as the distance that light travels … <\/p>\n

Detailed SolutionLight year is a measure 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":[1094],"tags":[1101,1140,1128],"class_list":["post-88388","post","type-post","status-publish","format-standard","hentry","category-upsc-nda-2","tag-1101","tag-measurement-unit","tag-physics","no-featured-image-padding"],"yoast_head":"\nLight year is a measure of<\/title>\n<meta name=\"description\" content=\"A light-year is defined as the distance that light travels in vacuum in one Julian year (365.25 days). Because light travels at a finite, constant speed in vacuum, the distance it covers over a fixed period of time is a specific value. 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