{"id":87532,"date":"2025-06-01T06:47:05","date_gmt":"2025-06-01T06:47:05","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=87532"},"modified":"2025-06-01T06:47:05","modified_gmt":"2025-06-01T06:47:05","slug":"which-one-of-the-following-statements-is-correct-24","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-24\/","title":{"rendered":"Which one of the following statements is correct ?"},"content":{"rendered":"<p>Which one of the following statements is correct ?<\/p>\n<p>[amp_mcq option1=&#8221;Any energy transfer that does not involve temperature difference in some way is not heat&#8221; option2=&#8221;Any energy transfer always requires a temperature difference&#8221; option3=&#8221;On heating the length and volume of the object remain exactly the same&#8221; option4=&#8221;Whenever there is a temperature difference, heat is the only way of energy transfer&#8221; correct=&#8221;option1&#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\">\nThis question is about the definition and characteristics of heat and energy transfer in physics. Heat is a specific mode of energy transfer.<br \/>\n<\/section>\n<section id=\"pyq-key-points\">\nLet&#8217;s analyze each statement:<br \/>\nA) Any energy transfer that does not involve temperature difference in some way is not heat: This statement is correct. Heat is defined as energy transferred from a hotter object to a colder object due to a temperature difference. Energy can also be transferred as work (e.g., mechanical work), which does not require a temperature difference. Therefore, energy transfer that doesn&#8217;t involve a temperature difference is not heat.<br \/>\nB) Any energy transfer always requires a temperature difference: This is incorrect. Energy can be transferred as work (mechanical, electrical, etc.), which does not require a temperature difference.<br \/>\nC) On heating the length and volume of the object remain exactly the same: This is incorrect. When most objects are heated, they undergo thermal expansion, meaning their length, area, and volume increase (though some exceptions exist like water between 0\u00b0C and 4\u00b0C).<br \/>\nD) Whenever there is a temperature difference, heat is the only way of energy transfer: This is incorrect. While a temperature difference causes heat transfer (conduction, convection, radiation), other forms of energy transfer, such as work done on or by the system, can also occur simultaneously, even if there is a temperature difference.<br \/>\n<\/section>\n<section id=\"pyq-additional-information\">\nThe First Law of Thermodynamics states that the change in internal energy of a system is equal to the heat added to the system minus the work done by the system ($\\Delta U = Q &#8211; W$). This equation clearly distinguishes between heat (Q) and work (W) as two primary modes of energy transfer. Heat is driven by temperature difference, while work is driven by forces and displacement.<br \/>\n<\/section>\n","protected":false},"excerpt":{"rendered":"<p>Which one of the following statements is correct ? [amp_mcq option1=&#8221;Any energy transfer that does not involve temperature difference in some way is not heat&#8221; option2=&#8221;Any energy transfer always requires a temperature difference&#8221; option3=&#8221;On heating the length and volume of the object remain exactly the same&#8221; option4=&#8221;Whenever there is a temperature difference, heat is the &#8230; <\/p>\n<p class=\"read-more-container\"><a title=\"Which one of the following statements is correct ?\" class=\"read-more button\" href=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-24\/#more-87532\">Detailed Solution<span class=\"screen-reader-text\">Which one of the following statements is correct ?<\/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":[1114,1130,1128],"class_list":["post-87532","post","type-post","status-publish","format-standard","hentry","category-upsc-nda-1","tag-1114","tag-heat-and-thermodynamics","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 statements is correct ?<\/title>\n<meta name=\"description\" content=\"This question is about the definition and characteristics of heat and energy transfer in physics. Heat is a specific mode of energy transfer. Let&#039;s analyze each statement: A) Any energy transfer that does not involve temperature difference in some way is not heat: This statement is correct. Heat is defined as energy transferred from a hotter object to a colder object due to a temperature difference. Energy can also be transferred as work (e.g., mechanical work), which does not require a temperature difference. Therefore, energy transfer that doesn&#039;t involve a temperature difference is not heat. B) Any energy transfer always requires a temperature difference: This is incorrect. Energy can be transferred as work (mechanical, electrical, etc.), which does not require a temperature difference. C) On heating the length and volume of the object remain exactly the same: This is incorrect. When most objects are heated, they undergo thermal expansion, meaning their length, area, and volume increase (though some exceptions exist like water between 0\u00b0C and 4\u00b0C). D) Whenever there is a temperature difference, heat is the only way of energy transfer: This is incorrect. While a temperature difference causes heat transfer (conduction, convection, radiation), other forms of energy transfer, such as work done on or by the system, can also occur simultaneously, even if there is a temperature difference.\" \/>\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-statements-is-correct-24\/\" \/>\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 statements is correct ?\" \/>\n<meta property=\"og:description\" content=\"This question is about the definition and characteristics of heat and energy transfer in physics. Heat is a specific mode of energy transfer. Let&#039;s analyze each statement: A) Any energy transfer that does not involve temperature difference in some way is not heat: This statement is correct. Heat is defined as energy transferred from a hotter object to a colder object due to a temperature difference. Energy can also be transferred as work (e.g., mechanical work), which does not require a temperature difference. Therefore, energy transfer that doesn&#039;t involve a temperature difference is not heat. B) Any energy transfer always requires a temperature difference: This is incorrect. Energy can be transferred as work (mechanical, electrical, etc.), which does not require a temperature difference. C) On heating the length and volume of the object remain exactly the same: This is incorrect. When most objects are heated, they undergo thermal expansion, meaning their length, area, and volume increase (though some exceptions exist like water between 0\u00b0C and 4\u00b0C). D) Whenever there is a temperature difference, heat is the only way of energy transfer: This is incorrect. While a temperature difference causes heat transfer (conduction, convection, radiation), other forms of energy transfer, such as work done on or by the system, can also occur simultaneously, even if there is a temperature difference.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-24\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2025-06-01T06:47:05+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 statements is correct ?","description":"This question is about the definition and characteristics of heat and energy transfer in physics. Heat is a specific mode of energy transfer. Let's analyze each statement: A) Any energy transfer that does not involve temperature difference in some way is not heat: This statement is correct. Heat is defined as energy transferred from a hotter object to a colder object due to a temperature difference. Energy can also be transferred as work (e.g., mechanical work), which does not require a temperature difference. Therefore, energy transfer that doesn't involve a temperature difference is not heat. B) Any energy transfer always requires a temperature difference: This is incorrect. Energy can be transferred as work (mechanical, electrical, etc.), which does not require a temperature difference. C) On heating the length and volume of the object remain exactly the same: This is incorrect. When most objects are heated, they undergo thermal expansion, meaning their length, area, and volume increase (though some exceptions exist like water between 0\u00b0C and 4\u00b0C). D) Whenever there is a temperature difference, heat is the only way of energy transfer: This is incorrect. While a temperature difference causes heat transfer (conduction, convection, radiation), other forms of energy transfer, such as work done on or by the system, can also occur simultaneously, even if there is a temperature difference.","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-statements-is-correct-24\/","og_locale":"en_US","og_type":"article","og_title":"Which one of the following statements is correct ?","og_description":"This question is about the definition and characteristics of heat and energy transfer in physics. Heat is a specific mode of energy transfer. Let's analyze each statement: A) Any energy transfer that does not involve temperature difference in some way is not heat: This statement is correct. Heat is defined as energy transferred from a hotter object to a colder object due to a temperature difference. Energy can also be transferred as work (e.g., mechanical work), which does not require a temperature difference. Therefore, energy transfer that doesn't involve a temperature difference is not heat. B) Any energy transfer always requires a temperature difference: This is incorrect. Energy can be transferred as work (mechanical, electrical, etc.), which does not require a temperature difference. C) On heating the length and volume of the object remain exactly the same: This is incorrect. When most objects are heated, they undergo thermal expansion, meaning their length, area, and volume increase (though some exceptions exist like water between 0\u00b0C and 4\u00b0C). D) Whenever there is a temperature difference, heat is the only way of energy transfer: This is incorrect. While a temperature difference causes heat transfer (conduction, convection, radiation), other forms of energy transfer, such as work done on or by the system, can also occur simultaneously, even if there is a temperature difference.","og_url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-24\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2025-06-01T06:47:05+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-statements-is-correct-24\/","url":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-24\/","name":"Which one of the following statements is correct ?","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2025-06-01T06:47:05+00:00","dateModified":"2025-06-01T06:47:05+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"description":"This question is about the definition and characteristics of heat and energy transfer in physics. Heat is a specific mode of energy transfer. Let's analyze each statement: A) Any energy transfer that does not involve temperature difference in some way is not heat: This statement is correct. Heat is defined as energy transferred from a hotter object to a colder object due to a temperature difference. Energy can also be transferred as work (e.g., mechanical work), which does not require a temperature difference. Therefore, energy transfer that doesn't involve a temperature difference is not heat. B) Any energy transfer always requires a temperature difference: This is incorrect. Energy can be transferred as work (mechanical, electrical, etc.), which does not require a temperature difference. C) On heating the length and volume of the object remain exactly the same: This is incorrect. When most objects are heated, they undergo thermal expansion, meaning their length, area, and volume increase (though some exceptions exist like water between 0\u00b0C and 4\u00b0C). D) Whenever there is a temperature difference, heat is the only way of energy transfer: This is incorrect. While a temperature difference causes heat transfer (conduction, convection, radiation), other forms of energy transfer, such as work done on or by the system, can also occur simultaneously, even if there is a temperature difference.","breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-24\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-24\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/which-one-of-the-following-statements-is-correct-24\/#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":"Which one of the following statements is correct ?"}]},{"@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\/87532","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=87532"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/87532\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=87532"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=87532"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=87532"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}