{"id":85963,"date":"2025-06-01T03:33:13","date_gmt":"2025-06-01T03:33:13","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=85963"},"modified":"2025-06-01T03:33:13","modified_gmt":"2025-06-01T03:33:13","slug":"an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/","title":{"rendered":"An echo is heard after 5 seconds of the production of sound which move"},"content":{"rendered":"

An echo is heard after 5 seconds of the production of sound which moves with a speed of 340 m\/s. What is the distance of the mountain from the source of sound which produced the echo ?<\/p>\n

[amp_mcq option1=”0.085 km” option2=”0.85 km” option3=”0.17 km” option4=”1.7 km” correct=”option2″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC CDS-2 – 2019<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
An echo is produced when sound reflects off a surface and returns to the source. The sound travels from the source to the mountain and then back from the mountain to the source. The total distance covered by the sound in 5 seconds is given by distance = speed \u00d7 time = 340 m\/s \u00d7 5 s = 1700 meters. This total distance is twice the distance between the source and the mountain (since the sound goes there and back). Therefore, the distance of the mountain from the source is half of the total distance, which is 1700 m \/ 2 = 850 meters.<\/section>\n
In an echo scenario, the time measured is for the sound’s round trip (source to obstacle and back), so the distance to the obstacle is half the total distance traveled by the sound.<\/section>\n
To convert meters to kilometers, divide by 1000. So, 850 meters = 850 \/ 1000 km = 0.85 km. This matches option B.<\/section>\n","protected":false},"excerpt":{"rendered":"

An echo is heard after 5 seconds of the production of sound which moves with a speed of 340 m\/s. What is the distance of the mountain from the source of sound which produced the echo ? [amp_mcq option1=”0.085 km” option2=”0.85 km” option3=”0.17 km” option4=”1.7 km” correct=”option2″] This question was previously asked in UPSC CDS-2 … <\/p>\n

Detailed SolutionAn echo is heard after 5 seconds of the production of sound which move<\/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":[1088],"tags":[1119,1128,1147],"class_list":["post-85963","post","type-post","status-publish","format-standard","hentry","category-upsc-cds-2","tag-1119","tag-physics","tag-sound","no-featured-image-padding"],"yoast_head":"\nAn echo is heard after 5 seconds of the production of sound which move<\/title>\n<meta name=\"description\" content=\"An echo is produced when sound reflects off a surface and returns to the source. The sound travels from the source to the mountain and then back from the mountain to the source. The total distance covered by the sound in 5 seconds is given by distance = speed \u00d7 time = 340 m\/s \u00d7 5 s = 1700 meters. This total distance is twice the distance between the source and the mountain (since the sound goes there and back). Therefore, the distance of the mountain from the source is half of the total distance, which is 1700 m \/ 2 = 850 meters. In an echo scenario, the time measured is for the sound's round trip (source to obstacle and back), so the distance to the obstacle is half the total distance traveled by the sound.\" \/>\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\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"An echo is heard after 5 seconds of the production of sound which move\" \/>\n<meta property=\"og:description\" content=\"An echo is produced when sound reflects off a surface and returns to the source. The sound travels from the source to the mountain and then back from the mountain to the source. The total distance covered by the sound in 5 seconds is given by distance = speed \u00d7 time = 340 m\/s \u00d7 5 s = 1700 meters. This total distance is twice the distance between the source and the mountain (since the sound goes there and back). Therefore, the distance of the mountain from the source is half of the total distance, which is 1700 m \/ 2 = 850 meters. In an echo scenario, the time measured is for the sound's round trip (source to obstacle and back), so the distance to the obstacle is half the total distance traveled by the sound.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T03:33:13+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":"An echo is heard after 5 seconds of the production of sound which move","description":"An echo is produced when sound reflects off a surface and returns to the source. The sound travels from the source to the mountain and then back from the mountain to the source. The total distance covered by the sound in 5 seconds is given by distance = speed \u00d7 time = 340 m\/s \u00d7 5 s = 1700 meters. This total distance is twice the distance between the source and the mountain (since the sound goes there and back). Therefore, the distance of the mountain from the source is half of the total distance, which is 1700 m \/ 2 = 850 meters. In an echo scenario, the time measured is for the sound's round trip (source to obstacle and back), so the distance to the obstacle is half the total distance traveled by the sound.","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\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/","og_locale":"en_US","og_type":"article","og_title":"An echo is heard after 5 seconds of the production of sound which move","og_description":"An echo is produced when sound reflects off a surface and returns to the source. The sound travels from the source to the mountain and then back from the mountain to the source. The total distance covered by the sound in 5 seconds is given by distance = speed \u00d7 time = 340 m\/s \u00d7 5 s = 1700 meters. This total distance is twice the distance between the source and the mountain (since the sound goes there and back). Therefore, the distance of the mountain from the source is half of the total distance, which is 1700 m \/ 2 = 850 meters. In an echo scenario, the time measured is for the sound's round trip (source to obstacle and back), so the distance to the obstacle is half the total distance traveled by the sound.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T03:33:13+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\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/","url":"https:\/\/exam.pscnotes.com\/mcq\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/","name":"An echo is heard after 5 seconds of the production of sound which move","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T03:33:13+00:00","dateModified":"2025-06-01T03:33:13+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"An echo is produced when sound reflects off a surface and returns to the source. The sound travels from the source to the mountain and then back from the mountain to the source. The total distance covered by the sound in 5 seconds is given by distance = speed \u00d7 time = 340 m\/s \u00d7 5 s = 1700 meters. This total distance is twice the distance between the source and the mountain (since the sound goes there and back). Therefore, the distance of the mountain from the source is half of the total distance, which is 1700 m \/ 2 = 850 meters. In an echo scenario, the time measured is for the sound's round trip (source to obstacle and back), so the distance to the obstacle is half the total distance traveled by the sound.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/an-echo-is-heard-after-5-seconds-of-the-production-of-sound-which-move\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CDS-2","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-cds-2\/"},{"@type":"ListItem","position":3,"name":"An echo is heard after 5 seconds of the production of sound which move"}]},{"@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\/85963","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=85963"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/85963\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=85963"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=85963"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=85963"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}