{"id":93126,"date":"2025-06-01T11:42:23","date_gmt":"2025-06-01T11:42:23","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=93126"},"modified":"2025-06-01T11:42:23","modified_gmt":"2025-06-01T11:42:23","slug":"which-one-of-the-following-materials-cannot-be-used-to-make-a-lens","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/","title":{"rendered":"Which one of the following materials cannot be used to make a lens ?"},"content":{"rendered":"<p>Which one of the following materials cannot be used to make a lens ?<\/p>\n<p>[amp_mcq option1=&#8221;Water&#8221; option2=&#8221;Glass&#8221; option3=&#8221;Plastic&#8221; option4=&#8221;Clay&#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 CISF-AC-EXE &#8211; 2022<\/div>\n<\/div>\n<div class=\"pyq-exam-psc-buttons\"><a href=\"\/pyq\/pyq-upsc-cisf-ac-exe-2022.pdf\" target=\"_blank\" class=\"psc-pdf-button\" rel=\"noopener\">Download PDF<\/a><a href=\"\/pyq-upsc-cisf-ac-exe-2022\" target=\"_blank\" class=\"psc-attempt-button\" rel=\"noopener\">Attempt Online<\/a><\/div>\n<\/div>\n<section id=\"pyq-correct-answer\">\nA lens is an optical device that transmits and refracts light, causing the convergence or divergence of light rays. For a material to be used to make a lens, it must be transparent or at least translucent enough to allow light to pass through it and must have a refractive index different from the surrounding medium (usually air) so that refraction occurs.<br \/>\nLet&#8217;s examine the given options:<br \/>\nA) Water: Water is transparent and has a refractive index. Lenses can be made from water (e.g., water-filled lenses) or exist naturally (e.g., a droplet of water can act as a lens).<br \/>\nB) Glass: Glass is a common, transparent material with a suitable refractive index used extensively for making lenses.<br \/>\nC) Plastic: Many types of plastic are transparent and are widely used for making lenses, especially in eyeglasses, contact lenses, and camera lenses.<br \/>\nD) Clay: Clay is typically opaque (does not allow light to pass through) and therefore cannot be used to make a functional lens that refracts light in the required manner. While it can be molded, its opaqueness makes it unsuitable for transmitting images.<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\n&#8211; A lens works by refracting light, which requires the material to be transparent or translucent.<br \/>\n&#8211; The material must have a different refractive index from the surrounding medium.<br \/>\n&#8211; Opaque materials cannot be used to make standard lenses.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nMaterials like glass and plastic are commonly used because they are transparent, can be precisely shaped, and have stable optical properties. Water&#8217;s shape changes easily, making it less practical for stable lenses unless contained. Clay&#8217;s opaqueness fundamentally prevents it from being used for light transmission and refraction in the way a lens operates.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Which one of the following materials cannot be used to make a lens ? [amp_mcq option1=&#8221;Water&#8221; option2=&#8221;Glass&#8221; option3=&#8221;Plastic&#8221; option4=&#8221;Clay&#8221; correct=&#8221;option4&#8243;] This question was previously asked in UPSC CISF-AC-EXE &#8211; 2022 Download PDFAttempt Online A lens is an optical device that transmits and refracts light, causing the convergence or divergence of light rays. For a material &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"Which one of the following materials cannot be used to make a lens ?\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/#more-93126\">Detailed Solution<span class=\"screen-reader-text\">Which one of the following materials cannot be used to make a lens ?<\/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":[1089],"tags":[1108,1153,1128],"class_list":["post-93126","post","type-post","status-publish","format-standard","hentry","category-upsc-cisf-ac-exe","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>Which one of the following materials cannot be used to make a lens ?<\/title>\n<meta name=\"description\" content=\"A lens is an optical device that transmits and refracts light, causing the convergence or divergence of light rays. For a material to be used to make a lens, it must be transparent or at least translucent enough to allow light to pass through it and must have a refractive index different from the surrounding medium (usually air) so that refraction occurs. Let&#039;s examine the given options: A) Water: Water is transparent and has a refractive index. Lenses can be made from water (e.g., water-filled lenses) or exist naturally (e.g., a droplet of water can act as a lens). B) Glass: Glass is a common, transparent material with a suitable refractive index used extensively for making lenses. C) Plastic: Many types of plastic are transparent and are widely used for making lenses, especially in eyeglasses, contact lenses, and camera lenses. D) Clay: Clay is typically opaque (does not allow light to pass through) and therefore cannot be used to make a functional lens that refracts light in the required manner. While it can be molded, its opaqueness makes it unsuitable for transmitting images. - A lens works by refracting light, which requires the material to be transparent or translucent. - The material must have a different refractive index from the surrounding medium. - Opaque materials cannot be used to make standard lenses.\" \/>\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\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Which one of the following materials cannot be used to make a lens ?\" \/>\n<meta property=\"og:description\" content=\"A lens is an optical device that transmits and refracts light, causing the convergence or divergence of light rays. For a material to be used to make a lens, it must be transparent or at least translucent enough to allow light to pass through it and must have a refractive index different from the surrounding medium (usually air) so that refraction occurs. Let&#039;s examine the given options: A) Water: Water is transparent and has a refractive index. Lenses can be made from water (e.g., water-filled lenses) or exist naturally (e.g., a droplet of water can act as a lens). B) Glass: Glass is a common, transparent material with a suitable refractive index used extensively for making lenses. C) Plastic: Many types of plastic are transparent and are widely used for making lenses, especially in eyeglasses, contact lenses, and camera lenses. D) Clay: Clay is typically opaque (does not allow light to pass through) and therefore cannot be used to make a functional lens that refracts light in the required manner. While it can be molded, its opaqueness makes it unsuitable for transmitting images. - A lens works by refracting light, which requires the material to be transparent or translucent. - The material must have a different refractive index from the surrounding medium. - Opaque materials cannot be used to make standard lenses.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T11:42:23+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=\"2 minutes\" \/>\n<!-- \/ Yoast SEO Premium plugin. -->","yoast_head_json":{"title":"Which one of the following materials cannot be used to make a lens ?","description":"A lens is an optical device that transmits and refracts light, causing the convergence or divergence of light rays. For a material to be used to make a lens, it must be transparent or at least translucent enough to allow light to pass through it and must have a refractive index different from the surrounding medium (usually air) so that refraction occurs. Let's examine the given options: A) Water: Water is transparent and has a refractive index. Lenses can be made from water (e.g., water-filled lenses) or exist naturally (e.g., a droplet of water can act as a lens). B) Glass: Glass is a common, transparent material with a suitable refractive index used extensively for making lenses. C) Plastic: Many types of plastic are transparent and are widely used for making lenses, especially in eyeglasses, contact lenses, and camera lenses. D) Clay: Clay is typically opaque (does not allow light to pass through) and therefore cannot be used to make a functional lens that refracts light in the required manner. While it can be molded, its opaqueness makes it unsuitable for transmitting images. - A lens works by refracting light, which requires the material to be transparent or translucent. - The material must have a different refractive index from the surrounding medium. - Opaque materials cannot be used to make standard lenses.","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\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/","og_locale":"en_US","og_type":"article","og_title":"Which one of the following materials cannot be used to make a lens ?","og_description":"A lens is an optical device that transmits and refracts light, causing the convergence or divergence of light rays. For a material to be used to make a lens, it must be transparent or at least translucent enough to allow light to pass through it and must have a refractive index different from the surrounding medium (usually air) so that refraction occurs. Let's examine the given options: A) Water: Water is transparent and has a refractive index. Lenses can be made from water (e.g., water-filled lenses) or exist naturally (e.g., a droplet of water can act as a lens). B) Glass: Glass is a common, transparent material with a suitable refractive index used extensively for making lenses. C) Plastic: Many types of plastic are transparent and are widely used for making lenses, especially in eyeglasses, contact lenses, and camera lenses. D) Clay: Clay is typically opaque (does not allow light to pass through) and therefore cannot be used to make a functional lens that refracts light in the required manner. While it can be molded, its opaqueness makes it unsuitable for transmitting images. - A lens works by refracting light, which requires the material to be transparent or translucent. - The material must have a different refractive index from the surrounding medium. - Opaque materials cannot be used to make standard lenses.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T11:42:23+00:00","author":"rawan239","twitter_card":"summary_large_image","twitter_misc":{"Written by":"rawan239","Est. reading time":"2 minutes"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/","url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/","name":"Which one of the following materials cannot be used to make a lens ?","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T11:42:23+00:00","dateModified":"2025-06-01T11:42:23+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"A lens is an optical device that transmits and refracts light, causing the convergence or divergence of light rays. For a material to be used to make a lens, it must be transparent or at least translucent enough to allow light to pass through it and must have a refractive index different from the surrounding medium (usually air) so that refraction occurs. Let's examine the given options: A) Water: Water is transparent and has a refractive index. Lenses can be made from water (e.g., water-filled lenses) or exist naturally (e.g., a droplet of water can act as a lens). B) Glass: Glass is a common, transparent material with a suitable refractive index used extensively for making lenses. C) Plastic: Many types of plastic are transparent and are widely used for making lenses, especially in eyeglasses, contact lenses, and camera lenses. D) Clay: Clay is typically opaque (does not allow light to pass through) and therefore cannot be used to make a functional lens that refracts light in the required manner. While it can be molded, its opaqueness makes it unsuitable for transmitting images. - A lens works by refracting light, which requires the material to be transparent or translucent. - The material must have a different refractive index from the surrounding medium. - Opaque materials cannot be used to make standard lenses.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-materials-cannot-be-used-to-make-a-lens\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC CISF-AC-EXE","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-cisf-ac-exe\/"},{"@type":"ListItem","position":3,"name":"Which one of the following materials cannot be used to make a lens ?"}]},{"@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\/93126","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=93126"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/93126\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=93126"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=93126"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=93126"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}