{"id":50732,"date":"2024-04-15T23:14:33","date_gmt":"2024-04-15T23:14:33","guid":{"rendered":"https:\/\/exam.pscnotes.com\/mcq\/?p=50732"},"modified":"2024-04-15T23:14:33","modified_gmt":"2024-04-15T23:14:33","slug":"in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will","status":"publish","type":"post","link":"https:\/\/exam.pscnotes.com\/mcq\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/","title":{"rendered":"In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will"},"content":{"rendered":"<p>\r\n    <!-- Check if it's an AMP page -->\r\n            <!-- Non-AMP version -->\r\n        <div class=\"mcq-container\" data-quiz-id=\"quizState_6a978747b4ddf\">\r\n                                            <div class=\"option\" data-option-key=\"option1\" data-is-correct=\"false\">\r\n                    Remain unchanged                <\/div>\r\n                                            <div class=\"option\" data-option-key=\"option2\" data-is-correct=\"false\">\r\n                    Reduce to one-fourth value                <\/div>\r\n                                            <div class=\"option\" data-option-key=\"option3\" data-is-correct=\"true\">\r\n                    motor are doubled, the torque developed by the motor will A. Remain unchanged B. Reduce to one-fourth value C. Increase four folds                <\/div>\r\n                                            <div class=\"option\" data-option-key=\"option4\" data-is-correct=\"false\">\r\n                    Be doubled                <\/div>\r\n                            \r\n            <!-- Feedback messages for non-AMP -->\r\n            <div class=\"feedback\" data-feedback=\"wrong\">Answer is Right!<\/div>\r\n            <div class=\"feedback\" data-feedback=\"right\">Answer is Wrong!<\/div>\r\n        <\/div>\r\n\r\n        <script>\r\n        document.addEventListener('DOMContentLoaded', function () {\r\n            var containers = document.querySelectorAll('.mcq-container');\r\n\r\n            containers.forEach(function(container) {\r\n                var options = container.querySelectorAll('.option');\r\n                var feedbackSelect = container.querySelector('[data-feedback=\"select\"]');\r\n                var feedbackWrong = container.querySelector('[data-feedback=\"wrong\"]');\r\n                var feedbackRight = container.querySelector('[data-feedback=\"right\"]');\r\n\r\n                options.forEach(function(option) {\r\n                    option.addEventListener('click', function() {\r\n                        var selectedOption = option.getAttribute('data-option-key');\r\n                        var isCorrect = option.getAttribute('data-is-correct') === 'true';\r\n\r\n                        \/\/ Remove previous selections\r\n                        options.forEach(function(opt) {\r\n                            opt.classList.remove('correct', 'incorrect');\r\n                        });\r\n\r\n                        \/\/ Add the correct\/incorrect class\r\n                        if (isCorrect) {\r\n                            option.classList.add('correct');\r\n                            feedbackRight.hidden = false;\r\n                            feedbackWrong.hidden = true;\r\n                        } else {\r\n                            option.classList.add('incorrect');\r\n                            feedbackRight.hidden = true;\r\n                            feedbackWrong.hidden = false;\r\n                        }\r\n\r\n                        \/\/ Hide select feedback\r\n                        feedbackSelect.hidden = true;\r\n                    });\r\n                });\r\n            });\r\n        });\r\n        <\/script>\r\n    \r\n    <!--more--><\/p>\n<p>The correct answer is: <strong>C. Increase four folds<\/strong><\/p>\n<p>The torque developed by a DC motor is given by the following equation:<\/p>\n<p>$$T = K \\frac{V_a &#8211; Eb}{R}$$<\/p>\n<p>where:<\/p>\n<ul>\n<li>$T$ is the torque developed by the motor<\/li>\n<li>$K$ is the torque constant of the motor<\/li>\n<li>$V_a$ is the applied voltage to the motor<\/li>\n<li>$Eb$ is the back EMF of the motor<\/li>\n<li>$R$ is the armature resistance of the motor<\/li>\n<\/ul>\n<p>If the back EMF and the speed of the motor are doubled, then the torque developed by the motor will increase four folds. This is because the back EMF is proportional to the speed of the motor, and the torque constant is a constant. Therefore, the torque developed by the motor is proportional to the applied voltage to the motor divided by the back EMF of the motor. When the back EMF and the speed of the motor are doubled, the torque developed by the motor will increase four folds.<\/p>\n<p>Here is a brief explanation of each option:<\/p>\n<ul>\n<li>Option A: <div class=\"youtube-subscribe-container\">\r\n        <a href=\"https:\/\/www.youtube.com\/channel\/UCNHT8lW-JmLC68rjBfZhdkg?sub_confirmation=1\" target=\"_blank\" class=\"youtube-subscribe-button\">\r\n        <div class=\"telegram-channel-container\">\r\n        <a href=\"https:\/\/t.me\/pscnotes2025\" target=\"_blank\" class=\"telegram-channel-button\">\r\n            <span class=\"telegram-icon\">\r\n                <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 496 512\">\r\n                    <path fill=\"white\" d=\"M248,8C111,8,0,119,0,256s111,248,248,248s248-111,248-248S385,8,248,8z M362,177L320,367c-3,14-10,18-20,14l-56-41l-27,26 c-3,3-5,5-10,5l4-63L323,196c5-5-1-7-8-3l-98,62l-42-13c-9-3-10-9,2-14l162-63C351,160,365,164,362,177z\"\/>\r\n                <\/svg>\r\n            <\/span>\r\n            Join Our Telegram Channel\r\n        <\/a>\r\n    <\/div>     <span class=\"youtube-icon\">\r\n                <svg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" viewBox=\"0 0 576 512\">\r\n                    <path d=\"M549.7 124.1c-6.3-23.7-24.8-42.3-48.3-48.6C458.8 64 288 64 288 64S117.2 64 74.6 75.5c-23.5 6.3-42 24.9-48.3 48.6-11.4 42.9-11.4 132.3-11.4 132.3s0 89.4 11.4 132.3c6.3 23.7 24.8 41.5 48.3 47.8C117.2 448 288 448 288 448s170.8 0 213.4-11.5c23.5-6.3 42-24.2 48.3-47.8 11.4-42.9 11.4-132.3 11.4-132.3s0-89.4-11.4-132.3zm-317.5 213.5V175.2l142.7 81.2-142.7 81.2z\"\/>\r\n                <\/svg>\r\n            <\/span>\r\n            Subscribe on YouTube\r\n        <\/a>\r\n    <\/div> The torque developed by the motor will remain unchanged. This is not correct because the back EMF and the speed of the motor are doubled. When the back EMF and the speed of the motor are doubled, the torque developed by the motor will increase four folds.<\/li>\n<li>Option B: The torque developed by the motor will reduce to one-fourth value. This is not correct because the back EMF and the speed of the motor are doubled. When the back EMF and the speed of the motor are doubled, the torque developed by the motor will increase four folds.<\/li>\n<li>Option C: The torque developed by the motor will increase four folds. This is correct because the back EMF and the speed of the motor are doubled. When the back EMF and the speed of the motor are doubled, the torque developed by the motor will increase four folds.<\/li>\n<li>Option D: The torque developed by the motor will be doubled. This is not correct because the back EMF and the speed of the motor are doubled. When the back EMF and the speed of the motor are doubled, the torque developed by the motor will increase four folds.<\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>Subscribe on YouTube<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[743],"tags":[],"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>In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will<\/title>\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\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will\" \/>\n<meta property=\"og:description\" content=\"Join Our Telegram Channel Subscribe on YouTube\" \/>\n<meta property=\"og:url\" content=\"https:\/\/exam.pscnotes.com\/mcq\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/\" \/>\n<meta property=\"og:site_name\" content=\"MCQ and Quiz for Exams\" \/>\n<meta property=\"article:published_time\" content=\"2024-04-15T23:14:33+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":"In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will","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\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/","og_locale":"en_US","og_type":"article","og_title":"In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will","og_description":"Join Our Telegram Channel Subscribe on YouTube","og_url":"https:\/\/exam.pscnotes.com\/mcq\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/","og_site_name":"MCQ and Quiz for Exams","article_published_time":"2024-04-15T23:14:33+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\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/","url":"https:\/\/exam.pscnotes.com\/mcq\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/","name":"In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will","isPartOf":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#website"},"datePublished":"2024-04-15T23:14:33+00:00","dateModified":"2024-04-15T23:14:33+00:00","author":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/#\/schema\/person\/5807dafeb27d2ec82344d6cbd6c3d209"},"breadcrumb":{"@id":"https:\/\/exam.pscnotes.com\/mcq\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/#breadcrumb"},"inLanguage":"en-US","potentialAction":[{"@type":"ReadAction","target":["https:\/\/exam.pscnotes.com\/mcq\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/exam.pscnotes.com\/mcq\/in-case-the-back-e-m-f-and-the-speed-of-a-d-c-motor-are-doubled-the-torque-developed-by-the-motor-will\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/exam.pscnotes.com\/mcq\/"},{"@type":"ListItem","position":2,"name":"mcq","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/mcq\/"},{"@type":"ListItem","position":3,"name":"Electrical engineering","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/mcq\/electrical-engineering\/"},{"@type":"ListItem","position":4,"name":"D.c. Motors","item":"https:\/\/exam.pscnotes.com\/mcq\/category\/mcq\/electrical-engineering\/d-c-motors\/"},{"@type":"ListItem","position":5,"name":"In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will"}]},{"@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\/d97f17072bfa490596c8f78363955d55?s=96&d=mm&r=g","contentUrl":"https:\/\/secure.gravatar.com\/avatar\/d97f17072bfa490596c8f78363955d55?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\/50732"}],"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=50732"}],"version-history":[{"count":0,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/posts\/50732\/revisions"}],"wp:attachment":[{"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/media?parent=50732"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/categories?post=50732"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/exam.pscnotes.com\/mcq\/wp-json\/wp\/v2\/tags?post=50732"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}