{"id":86997,"date":"2025-06-01T04:25:09","date_gmt":"2025-06-01T04:25:09","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=86997"},"modified":"2025-06-01T04:25:09","modified_gmt":"2025-06-01T04:25:09","slug":"which-one-of-the-following-quantities-is-dimensionless","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-quantities-is-dimensionless\/","title":{"rendered":"Which one of the following quantities is dimensionless?"},"content":{"rendered":"

Which one of the following quantities is dimensionless?<\/p>\n

[amp_mcq option1=”Specific weight” option2=”Specific heat” option3=”Specific density” option4=”Specific gravity” correct=”option4″]<\/p>\n

\n
\n
This question was previously asked in<\/div>\n
UPSC Geoscientist – 2023<\/div>\n<\/div>\n
Download PDF<\/a>Attempt Online<\/a><\/div>\n<\/div>\n
\nA dimensionless quantity is a quantity without any physical units or dimensions.
\nSpecific weight is weight per unit volume (Force\/Volume), with units like N\/m\u00b3 or lb\/ft\u00b3. It has dimensions [M L\u207b\u00b2 T\u207b\u00b2].
\nSpecific heat (or specific heat capacity) is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree. It has units like J\/(kg\u00b7K) or cal\/(g\u00b7\u00b0C), and dimensions [L\u00b2 T\u207b\u00b2 \u03b8\u207b\u00b9].
\nSpecific density is often used interchangeably with relative density or specific gravity, which is the ratio of the density of a substance to the density of a reference substance (like water). In this context, it is dimensionless. However, sometimes ‘specific density’ might be used ambiguously.
\nSpecific gravity is precisely defined as the ratio of the density of a substance to the density of a reference substance. As it is a ratio of two quantities with the same dimensions (density), it is dimensionless.
\nGiven the options, Specific Gravity (D) is unambiguously a dimensionless quantity. Specific density (C) would also be dimensionless if it means relative density, but specific gravity is the more commonly used term for this dimensionless ratio. If specific density were interpreted as density per unit mass (1\/volume), it would be dimensional. Therefore, Specific Gravity is the correct answer.
\n<\/section>\n
\nSpecific gravity is defined as the ratio of the density of a substance to the density of a standard substance, making it a dimensionless quantity.
\n<\/section>\n
\nDimensionless quantities are useful as they can be used in ratios and provide relative measures without depending on the system of units. Examples include Reynolds number, Mach number, friction coefficient, and angles (in radians).
\n<\/section>\n","protected":false},"excerpt":{"rendered":"

Which one of the following quantities is dimensionless? [amp_mcq option1=”Specific weight” option2=”Specific heat” option3=”Specific density” option4=”Specific gravity” correct=”option4″] This question was previously asked in UPSC Geoscientist – 2023 Download PDFAttempt Online A dimensionless quantity is a quantity without any physical units or dimensions. Specific weight is weight per unit volume (Force\/Volume), with units like N\/m\u00b3 … <\/p>\n

Detailed SolutionWhich one of the following quantities is dimensionless?<\/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":[1091],"tags":[1105,1140,1128],"class_list":["post-86997","post","type-post","status-publish","format-standard","hentry","category-upsc-geoscientist","tag-1105","tag-measurement-unit","tag-physics","no-featured-image-padding"],"yoast_head":"\nWhich one of the following quantities is dimensionless?<\/title>\n<meta name=\"description\" content=\"A dimensionless quantity is a quantity without any physical units or dimensions. Specific weight is weight per unit volume (Force\/Volume), with units like N\/m\u00b3 or lb\/ft\u00b3. It has dimensions [M L\u207b\u00b2 T\u207b\u00b2]. Specific heat (or specific heat capacity) is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree. It has units like J\/(kg\u00b7K) or cal\/(g\u00b7\u00b0C), and dimensions [L\u00b2 T\u207b\u00b2 \u03b8\u207b\u00b9]. Specific density is often used interchangeably with relative density or specific gravity, which is the ratio of the density of a substance to the density of a reference substance (like water). In this context, it is dimensionless. However, sometimes 'specific density' might be used ambiguously. Specific gravity is precisely defined as the ratio of the density of a substance to the density of a reference substance. As it is a ratio of two quantities with the same dimensions (density), it is dimensionless. Given the options, Specific Gravity (D) is unambiguously a dimensionless quantity. Specific density (C) would also be dimensionless if it means relative density, but specific gravity is the more commonly used term for this dimensionless ratio. If specific density were interpreted as density per unit mass (1\/volume), it would be dimensional. Therefore, Specific Gravity is the correct answer. Specific gravity is defined as the ratio of the density of a substance to the density of a standard substance, making it a dimensionless quantity.\" \/>\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-quantities-is-dimensionless\/\" \/>\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 quantities is dimensionless?\" \/>\n<meta property=\"og:description\" content=\"A dimensionless quantity is a quantity without any physical units or dimensions. Specific weight is weight per unit volume (Force\/Volume), with units like N\/m\u00b3 or lb\/ft\u00b3. It has dimensions [M L\u207b\u00b2 T\u207b\u00b2]. Specific heat (or specific heat capacity) is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree. It has units like J\/(kg\u00b7K) or cal\/(g\u00b7\u00b0C), and dimensions [L\u00b2 T\u207b\u00b2 \u03b8\u207b\u00b9]. Specific density is often used interchangeably with relative density or specific gravity, which is the ratio of the density of a substance to the density of a reference substance (like water). In this context, it is dimensionless. However, sometimes 'specific density' might be used ambiguously. Specific gravity is precisely defined as the ratio of the density of a substance to the density of a reference substance. As it is a ratio of two quantities with the same dimensions (density), it is dimensionless. Given the options, Specific Gravity (D) is unambiguously a dimensionless quantity. Specific density (C) would also be dimensionless if it means relative density, but specific gravity is the more commonly used term for this dimensionless ratio. If specific density were interpreted as density per unit mass (1\/volume), it would be dimensional. Therefore, Specific Gravity is the correct answer. Specific gravity is defined as the ratio of the density of a substance to the density of a standard substance, making it a dimensionless quantity.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-quantities-is-dimensionless\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T04:25:09+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 quantities is dimensionless?","description":"A dimensionless quantity is a quantity without any physical units or dimensions. Specific weight is weight per unit volume (Force\/Volume), with units like N\/m\u00b3 or lb\/ft\u00b3. It has dimensions [M L\u207b\u00b2 T\u207b\u00b2]. Specific heat (or specific heat capacity) is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree. It has units like J\/(kg\u00b7K) or cal\/(g\u00b7\u00b0C), and dimensions [L\u00b2 T\u207b\u00b2 \u03b8\u207b\u00b9]. Specific density is often used interchangeably with relative density or specific gravity, which is the ratio of the density of a substance to the density of a reference substance (like water). In this context, it is dimensionless. However, sometimes 'specific density' might be used ambiguously. Specific gravity is precisely defined as the ratio of the density of a substance to the density of a reference substance. As it is a ratio of two quantities with the same dimensions (density), it is dimensionless. Given the options, Specific Gravity (D) is unambiguously a dimensionless quantity. Specific density (C) would also be dimensionless if it means relative density, but specific gravity is the more commonly used term for this dimensionless ratio. If specific density were interpreted as density per unit mass (1\/volume), it would be dimensional. Therefore, Specific Gravity is the correct answer. Specific gravity is defined as the ratio of the density of a substance to the density of a standard substance, making it a dimensionless quantity.","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-quantities-is-dimensionless\/","og_locale":"en_US","og_type":"article","og_title":"Which one of the following quantities is dimensionless?","og_description":"A dimensionless quantity is a quantity without any physical units or dimensions. Specific weight is weight per unit volume (Force\/Volume), with units like N\/m\u00b3 or lb\/ft\u00b3. It has dimensions [M L\u207b\u00b2 T\u207b\u00b2]. Specific heat (or specific heat capacity) is the amount of heat energy required to raise the temperature of a unit mass of a substance by one degree. It has units like J\/(kg\u00b7K) or cal\/(g\u00b7\u00b0C), and dimensions [L\u00b2 T\u207b\u00b2 \u03b8\u207b\u00b9]. Specific density is often used interchangeably with relative density or specific gravity, which is the ratio of the density of a substance to the density of a reference substance (like water). In this context, it is dimensionless. However, sometimes 'specific density' might be used ambiguously. Specific gravity is precisely defined as the ratio of the density of a substance to the density of a reference substance. As it is a ratio of two quantities with the same dimensions (density), it is dimensionless. Given the options, Specific Gravity (D) is unambiguously a dimensionless quantity. Specific density (C) would also be dimensionless if it means relative density, but specific gravity is the more commonly used term for this dimensionless ratio. If specific density were interpreted as density per unit mass (1\/volume), it would be dimensional. Therefore, Specific Gravity is the correct answer. Specific gravity is defined as the ratio of the density of a substance to the density of a standard substance, making it a dimensionless quantity.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-quantities-is-dimensionless\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T04:25:09+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-quantities-is-dimensionless\/","url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-quantities-is-dimensionless\/","name":"Which one of the following quantities is dimensionless?","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T04:25:09+00:00","dateModified":"2025-06-01T04:25:09+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"A dimensionless quantity is a quantity without any physical units or dimensions. 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Given the options, Specific Gravity (D) is unambiguously a dimensionless quantity. Specific density (C) would also be dimensionless if it means relative density, but specific gravity is the more commonly used term for this dimensionless ratio. If specific density were interpreted as density per unit mass (1\/volume), it would be dimensional. Therefore, Specific Gravity is the correct answer. Specific gravity is defined as the ratio of the density of a substance to the density of a standard substance, making it a dimensionless quantity.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-quantities-is-dimensionless\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-quantities-is-dimensionless\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-quantities-is-dimensionless\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"UPSC Geoscientist","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/upsc-geoscientist\/"},{"@type":"ListItem","position":3,"name":"Which one of the following quantities is dimensionless?"}]},{"@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\/86997","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=86997"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/86997\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=86997"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=86997"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=86997"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}