{"id":87586,"date":"2025-06-01T06:48:15","date_gmt":"2025-06-01T06:48:15","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=87586"},"modified":"2025-06-01T06:48:15","modified_gmt":"2025-06-01T06:48:15","slug":"two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/","title":{"rendered":"Two convex lenses with power 2 dioptre are kept in contact with each o"},"content":{"rendered":"<p>Two convex lenses with power 2 dioptre are kept in contact with each other. The focal length of the combined lens system is<\/p>\n<p>[amp_mcq option1=&#8221;0.10 m&#8221; option2=&#8221;2 m&#8221; option3=&#8221;4 m&#8221; option4=&#8221;0.25 m&#8221; correct=&#8221;option4&#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 NDA-1 &#8211; 2018<\/div>\n<\/div>\n<div class=\"pyq-exam-psc-buttons\"><a href=\"\/pyq\/pyq-upsc-nda-1-2018.pdf\" target=\"_blank\" class=\"psc-pdf-button\" rel=\"noopener\">Download PDF<\/a><a href=\"\/pyq-upsc-nda-1-2018\" target=\"_blank\" class=\"psc-attempt-button\" rel=\"noopener\">Attempt Online<\/a><\/div>\n<\/div>\n<section id=\"pyq-correct-answer\">\nWhen two thin lenses are kept in contact, the total power of the combination is the sum of the individual powers. The power of a lens (P) is given by the reciprocal of its focal length (f) in meters, i.e., P = 1\/f.<br \/>\nGiven the power of each lens is 2 Dioptre, the total power of the combined system is $P_{total} = P_1 + P_2 = 2 \\, \\text{D} + 2 \\, \\text{D} = 4 \\, \\text{D}$.<br \/>\nThe focal length of the combined lens system (F) is the reciprocal of the total power: $F = 1 \/ P_{total} = 1 \/ 4 \\, \\text{D} = 0.25 \\, \\text{meters}$.<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\nThe power of lenses is additive when they are placed in contact. This property is useful for designing lens systems.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nDioptre (D) is the unit of power of a lens, defined as the reciprocal of the focal length in meters. A convex lens has positive power and focal length, while a concave lens has negative power and focal length.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Two convex lenses with power 2 dioptre are kept in contact with each other. The focal length of the combined lens system is [amp_mcq option1=&#8221;0.10 m&#8221; option2=&#8221;2 m&#8221; option3=&#8221;4 m&#8221; option4=&#8221;0.25 m&#8221; correct=&#8221;option4&#8243;] This question was previously asked in UPSC NDA-1 &#8211; 2018 Download PDFAttempt Online When two thin lenses are kept in contact, the &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"Two convex lenses with power 2 dioptre are kept in contact with each o\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/#more-87586\">Detailed Solution<span class=\"screen-reader-text\">Two convex lenses with power 2 dioptre are kept in contact with each o<\/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":[1114,1153,1128],"class_list":["post-87586","post","type-post","status-publish","format-standard","hentry","category-upsc-nda-1","tag-1114","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>Two convex lenses with power 2 dioptre are kept in contact with each o<\/title>\n<meta name=\"description\" content=\"When two thin lenses are kept in contact, the total power of the combination is the sum of the individual powers. The power of a lens (P) is given by the reciprocal of its focal length (f) in meters, i.e., P = 1\/f. Given the power of each lens is 2 Dioptre, the total power of the combined system is $P_{total} = P_1 + P_2 = 2 , text{D} + 2 , text{D} = 4 , text{D}$. The focal length of the combined lens system (F) is the reciprocal of the total power: $F = 1 \/ P_{total} = 1 \/ 4 , text{D} = 0.25 , text{meters}$. The power of lenses is additive when they are placed in contact. This property is useful for designing lens systems.\" \/>\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\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Two convex lenses with power 2 dioptre are kept in contact with each o\" \/>\n<meta property=\"og:description\" content=\"When two thin lenses are kept in contact, the total power of the combination is the sum of the individual powers. The power of a lens (P) is given by the reciprocal of its focal length (f) in meters, i.e., P = 1\/f. Given the power of each lens is 2 Dioptre, the total power of the combined system is $P_{total} = P_1 + P_2 = 2 , text{D} + 2 , text{D} = 4 , text{D}$. The focal length of the combined lens system (F) is the reciprocal of the total power: $F = 1 \/ P_{total} = 1 \/ 4 , text{D} = 0.25 , text{meters}$. The power of lenses is additive when they are placed in contact. This property is useful for designing lens systems.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T06:48:15+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":"Two convex lenses with power 2 dioptre are kept in contact with each o","description":"When two thin lenses are kept in contact, the total power of the combination is the sum of the individual powers. The power of a lens (P) is given by the reciprocal of its focal length (f) in meters, i.e., P = 1\/f. Given the power of each lens is 2 Dioptre, the total power of the combined system is $P_{total} = P_1 + P_2 = 2 , text{D} + 2 , text{D} = 4 , text{D}$. The focal length of the combined lens system (F) is the reciprocal of the total power: $F = 1 \/ P_{total} = 1 \/ 4 , text{D} = 0.25 , text{meters}$. The power of lenses is additive when they are placed in contact. This property is useful for designing lens systems.","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\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/","og_locale":"en_US","og_type":"article","og_title":"Two convex lenses with power 2 dioptre are kept in contact with each o","og_description":"When two thin lenses are kept in contact, the total power of the combination is the sum of the individual powers. The power of a lens (P) is given by the reciprocal of its focal length (f) in meters, i.e., P = 1\/f. Given the power of each lens is 2 Dioptre, the total power of the combined system is $P_{total} = P_1 + P_2 = 2 , text{D} + 2 , text{D} = 4 , text{D}$. The focal length of the combined lens system (F) is the reciprocal of the total power: $F = 1 \/ P_{total} = 1 \/ 4 , text{D} = 0.25 , text{meters}$. The power of lenses is additive when they are placed in contact. This property is useful for designing lens systems.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T06:48:15+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\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/","url":"https:\/\/exam.pscnotes.com\/mcq\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/","name":"Two convex lenses with power 2 dioptre are kept in contact with each o","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T06:48:15+00:00","dateModified":"2025-06-01T06:48:15+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"When two thin lenses are kept in contact, the total power of the combination is the sum of the individual powers. The power of a lens (P) is given by the reciprocal of its focal length (f) in meters, i.e., P = 1\/f. Given the power of each lens is 2 Dioptre, the total power of the combined system is $P_{total} = P_1 + P_2 = 2 \\, \\text{D} + 2 \\, \\text{D} = 4 \\, \\text{D}$. The focal length of the combined lens system (F) is the reciprocal of the total power: $F = 1 \/ P_{total} = 1 \/ 4 \\, \\text{D} = 0.25 \\, \\text{meters}$. The power of lenses is additive when they are placed in contact. This property is useful for designing lens systems.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/two-convex-lenses-with-power-2-dioptre-are-kept-in-contact-with-each-o\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC NDA-1","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-nda-1\/"},{"@type":"ListItem","position":3,"name":"Two convex lenses with power 2 dioptre are kept in contact with each o"}]},{"@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\/87586","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=87586"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/87586\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=87586"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=87586"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=87586"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}