{"id":1713,"date":"2015-12-31T02:59:09","date_gmt":"2015-12-31T02:59:09","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=1713"},"modified":"2024-12-04T16:36:25","modified_gmt":"2024-12-04T16:36:25","slug":"exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica\/","title":{"rendered":"Electric energy &#8211; EN Resolution"},"content":{"rendered":"<h1 class=\"page-title\">ELECTRIC ENERGY \u2013 RESOLUTION<\/h1>\n<div class=\"entry clearfix\">\n<p align=\"CENTER\"><b>Entrance exam exercises with commented solutions on<\/b><\/p>\n<p align=\"CENTER\"><b>Electrical power \u2013 Electrical energy<\/b><\/p>\n<p><b>01-(UNICAMP-SP)<\/b><b>\u00a0Consider the following equipment operating at maximum power during<\/b><\/p>\n<div class=\"google-auto-placed ap_container\">\n<p>&nbsp;<\/p>\n<div id=\"aswift_10_host\"><iframe id=\"aswift_10\" tabindex=\"0\" title=\"Advertisement\" src=\"https:\/\/googleads.g.doubleclick.net\/pagead\/ads?gdpr=0&amp;us_privacy=1---&amp;gpp_sid=-1&amp;client=ca-pub-4904230854272924&amp;output=html&amp;h=280&amp;adk=2572008957&amp;adf=2972338631&amp;w=890&amp;abgtt=7&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1731072195&amp;num_ads=1&amp;rafmt=1&amp;armr=3&amp;sem=mc&amp;pwprc=4065565381&amp;ad_type=text_image&amp;format=890x280&amp;url=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Feletricidade%2Feletrodinamica%2Fpotencia-eletrica-energia-eletrica%2Fexercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica%2F&amp;host=ca-host-pub-2644536267352236&amp;fwr=0&amp;pra=3&amp;rh=200&amp;rw=890&amp;rpe=1&amp;resp_fmts=3&amp;wgl=1&amp;fa=27&amp;uach=WyJXaW5kb3dzIiwiMTUuMC4wIiwieDg2IiwiIiwiMTIwLjAuNjA5OS43MiIsbnVsbCwwLG51bGwsIjY0IixbWyJOb3RfQSBCcmFuZCIsIjguMC4wLjAiXSxbIkNocm9taXVtIiwiMTIwLjAuNjA5OS43MiJdLFsiR29vZ2xlIENocm9tZSIsIjEyMC4wLjYwOTkuNzIiXV0sMF0.&amp;dt=1731072194557&amp;bpp=2&amp;bdt=5307&amp;idt=-M&amp;shv=r20241106&amp;mjsv=m202410310101&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D2fc0e8f762635b59%3AT%3D1724070743%3ART%3D1731072191%3AS%3DALNI_MY5o0gCt1iJgGxp5gzyTHQ01LNs_Q&amp;eo_id_str=ID%3D1d14c7920cc7842b%3AT%3D1724070743%3ART%3D1731072191%3AS%3DAA-AfjaSoQ0jWyJl98idd6reyYjh&amp;prev_fmts=0x0%2C1200x280%2C300x600%2C300x600%2C300x600&amp;nras=3&amp;correlator=7304014780565&amp;frm=20&amp;pv=1&amp;u_tz=-180&amp;u_his=50&amp;u_h=768&amp;u_w=1366&amp;u_ah=720&amp;u_aw=1366&amp;u_cd=24&amp;u_sd=0.8&amp;dmc=4&amp;adx=199&amp;ady=836&amp;biw=1686&amp;bih=791&amp;scr_x=0&amp;scr_y=0&amp;eid=44759876%2C44759927%2C95346097%2C31088670%2C95343682%2C95344188%2C95344787%2C31088698%2C95335247%2C31088457%2C95345967%2C95347174&amp;oid=2&amp;psts=AOrYGsk88sw7EJcr2uB8As1vMD-C_UjLH8EnwtDwkfYwYjWHhn0j41tpPOdcYAMdtaJK96A0pCCTrMeCHlZZxwnFfcGemKdX%2CAOrYGsmMv1HHHKRt2eWIyrm-5ocE1aervc6jtV1VzrsmJICHGZNKSH6BqpHKj-e0Fw9cWYsf2jCQVEiUsydVkg&amp;pvsid=1596426275047371&amp;tmod=465429636&amp;uas=0&amp;nvt=1&amp;ref=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Fwp-admin%2Fpost.php%3Fpost%3D1713%26action%3Dedit&amp;fc=1408&amp;brdim=0%2C0%2C0%2C0%2C1366%2C0%2C1366%2C720%2C1707%2C791&amp;vis=1&amp;rsz=%7C%7Cs%7C&amp;abl=NS&amp;fu=128&amp;bc=31&amp;bz=0.8&amp;td=1&amp;tdf=0&amp;psd=W251bGwsbnVsbCxudWxsLDNd&amp;nt=1&amp;ifi=11&amp;uci=a!b&amp;btvi=4&amp;fsb=1&amp;dtd=1089\" name=\"aswift_10\" width=\"890\" height=\"0\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" sandbox=\"allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation\" data-google-container-id=\"a!b\" aria-label=\"Advertisement\" data-google-query-id=\"CO292LrqzIkDFdNIuAQdOo4KCw\" data-load-complete=\"true\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<p align=\"CENTER\"><img decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_445132f7.jpg\" alt=\"\" width=\"83\" height=\"72\" name=\"Imagem 6\" align=\"BOTTOM\" border=\"0\" \/><img decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_5d170007.jpg\" alt=\"\" width=\"138\" height=\"72\" name=\"Imagem 7\" align=\"BOTTOM\" border=\"0\" \/><img decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_ec42ec39.jpg\" alt=\"\" width=\"134\" height=\"72\" name=\"graphics8\" align=\"BOTTOM\" border=\"0\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_b2d2cd1d.jpg\" alt=\"\" width=\"105\" height=\"75\" name=\"Imagem 9\" align=\"BOTTOM\" border=\"0\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_cb8be9b9.jpg\" alt=\"\" width=\"115\" height=\"72\" name=\"graphics9\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>one hour: a 100W light bulb, a\u00a0Beetle\u00a0<a class=\"google-anno\" href=\"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica\/#\" data-google-vignette=\"false\" data-google-interstitial=\"false\">\u00a0<span class=\"google-anno-t\">engine , a truck engine, a 40W light bulb, an iron.<\/span><\/a><\/b><\/p>\n<div class=\"google-auto-placed ap_container\">\n<p>&nbsp;<\/p>\n<div id=\"aswift_11_host\"><iframe id=\"aswift_11\" tabindex=\"0\" title=\"Advertisement\" src=\"https:\/\/googleads.g.doubleclick.net\/pagead\/ads?gdpr=0&amp;us_privacy=1---&amp;gpp_sid=-1&amp;client=ca-pub-4904230854272924&amp;output=html&amp;h=280&amp;adk=2572008957&amp;adf=1241141201&amp;w=890&amp;abgtt=7&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1731072196&amp;num_ads=1&amp;rafmt=1&amp;armr=3&amp;sem=mc&amp;pwprc=4065565381&amp;ad_type=text_image&amp;format=890x280&amp;url=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Feletricidade%2Feletrodinamica%2Fpotencia-eletrica-energia-eletrica%2Fexercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica%2F&amp;host=ca-host-pub-2644536267352236&amp;fwr=0&amp;pra=3&amp;rh=200&amp;rw=890&amp;rpe=1&amp;resp_fmts=3&amp;wgl=1&amp;fa=27&amp;uach=WyJXaW5kb3dzIiwiMTUuMC4wIiwieDg2IiwiIiwiMTIwLjAuNjA5OS43MiIsbnVsbCwwLG51bGwsIjY0IixbWyJOb3RfQSBCcmFuZCIsIjguMC4wLjAiXSxbIkNocm9taXVtIiwiMTIwLjAuNjA5OS43MiJdLFsiR29vZ2xlIENocm9tZSIsIjEyMC4wLjYwOTkuNzIiXV0sMF0.&amp;dt=1731072194557&amp;bpp=22&amp;bdt=5307&amp;idt=-M&amp;shv=r20241106&amp;mjsv=m202410310101&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D2fc0e8f762635b59%3AT%3D1724070743%3ART%3D1731072191%3AS%3DALNI_MY5o0gCt1iJgGxp5gzyTHQ01LNs_Q&amp;eo_id_str=ID%3D1d14c7920cc7842b%3AT%3D1724070743%3ART%3D1731072191%3AS%3DAA-AfjaSoQ0jWyJl98idd6reyYjh&amp;prev_fmts=0x0%2C1200x280%2C300x600%2C300x600%2C300x600%2C890x280&amp;nras=4&amp;correlator=7304014780565&amp;frm=20&amp;pv=1&amp;u_tz=-180&amp;u_his=50&amp;u_h=768&amp;u_w=1366&amp;u_ah=720&amp;u_aw=1366&amp;u_cd=24&amp;u_sd=0.8&amp;dmc=4&amp;adx=199&amp;ady=1288&amp;biw=1686&amp;bih=791&amp;scr_x=0&amp;scr_y=0&amp;eid=44759876%2C44759927%2C95346097%2C31088670%2C95343682%2C95344188%2C95344787%2C31088698%2C95335247%2C31088457%2C95345967%2C95347174&amp;oid=2&amp;psts=AOrYGsk88sw7EJcr2uB8As1vMD-C_UjLH8EnwtDwkfYwYjWHhn0j41tpPOdcYAMdtaJK96A0pCCTrMeCHlZZxwnFfcGemKdX%2CAOrYGsmMv1HHHKRt2eWIyrm-5ocE1aervc6jtV1VzrsmJICHGZNKSH6BqpHKj-e0Fw9cWYsf2jCQVEiUsydVkg&amp;pvsid=1596426275047371&amp;tmod=465429636&amp;uas=0&amp;nvt=1&amp;ref=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Fwp-admin%2Fpost.php%3Fpost%3D1713%26action%3Dedit&amp;fc=1408&amp;brdim=0%2C0%2C0%2C0%2C1366%2C0%2C1366%2C720%2C1707%2C791&amp;vis=1&amp;rsz=%7C%7Cs%7C&amp;abl=NS&amp;fu=128&amp;bc=31&amp;bz=0.8&amp;td=1&amp;tdf=0&amp;psd=W251bGwsbnVsbCxudWxsLDNd&amp;nt=1&amp;ifi=12&amp;uci=a!c&amp;btvi=5&amp;fsb=1&amp;dtd=1549\" name=\"aswift_11\" width=\"890\" height=\"0\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" sandbox=\"allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation\" data-google-container-id=\"a!c\" aria-label=\"Advertisement\" data-google-query-id=\"CIfP7LrqzIkDFURLuAQdDtUTEg\" data-load-complete=\"true\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<p><b>a) Which lamp consumes less energy?<\/b><\/p>\n<div class=\"google-auto-placed ap_container\">\n<p>&nbsp;<\/p>\n<div id=\"aswift_12_host\"><iframe id=\"aswift_12\" tabindex=\"0\" title=\"Advertisement\" src=\"https:\/\/googleads.g.doubleclick.net\/pagead\/ads?gdpr=0&amp;us_privacy=1---&amp;gpp_sid=-1&amp;client=ca-pub-4904230854272924&amp;output=html&amp;h=280&amp;adk=2572008957&amp;adf=3456328566&amp;w=890&amp;abgtt=7&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1731072196&amp;num_ads=1&amp;rafmt=1&amp;armr=3&amp;sem=mc&amp;pwprc=4065565381&amp;ad_type=text_image&amp;format=890x280&amp;url=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Feletricidade%2Feletrodinamica%2Fpotencia-eletrica-energia-eletrica%2Fexercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica%2F&amp;host=ca-host-pub-2644536267352236&amp;fwr=0&amp;pra=3&amp;rh=200&amp;rw=890&amp;rpe=1&amp;resp_fmts=3&amp;wgl=1&amp;fa=27&amp;uach=WyJXaW5kb3dzIiwiMTUuMC4wIiwieDg2IiwiIiwiMTIwLjAuNjA5OS43MiIsbnVsbCwwLG51bGwsIjY0IixbWyJOb3RfQSBCcmFuZCIsIjguMC4wLjAiXSxbIkNocm9taXVtIiwiMTIwLjAuNjA5OS43MiJdLFsiR29vZ2xlIENocm9tZSIsIjEyMC4wLjYwOTkuNzIiXV0sMF0.&amp;dt=1731072194557&amp;bpp=13&amp;bdt=5307&amp;idt=-M&amp;shv=r20241106&amp;mjsv=m202410310101&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D2fc0e8f762635b59%3AT%3D1724070743%3ART%3D1731072191%3AS%3DALNI_MY5o0gCt1iJgGxp5gzyTHQ01LNs_Q&amp;eo_id_str=ID%3D1d14c7920cc7842b%3AT%3D1724070743%3ART%3D1731072191%3AS%3DAA-AfjaSoQ0jWyJl98idd6reyYjh&amp;prev_fmts=0x0%2C1200x280%2C300x600%2C300x600%2C300x600%2C890x280%2C890x280&amp;nras=5&amp;correlator=7304014780565&amp;frm=20&amp;pv=1&amp;u_tz=-180&amp;u_his=50&amp;u_h=768&amp;u_w=1366&amp;u_ah=720&amp;u_aw=1366&amp;u_cd=24&amp;u_sd=0.8&amp;dmc=4&amp;adx=199&amp;ady=1618&amp;biw=1686&amp;bih=791&amp;scr_x=0&amp;scr_y=0&amp;eid=44759876%2C44759927%2C95346097%2C31088670%2C95343682%2C95344188%2C95344787%2C31088698%2C95335247%2C31088457%2C95345967%2C95347174&amp;oid=2&amp;psts=AOrYGsk88sw7EJcr2uB8As1vMD-C_UjLH8EnwtDwkfYwYjWHhn0j41tpPOdcYAMdtaJK96A0pCCTrMeCHlZZxwnFfcGemKdX%2CAOrYGsmMv1HHHKRt2eWIyrm-5ocE1aervc6jtV1VzrsmJICHGZNKSH6BqpHKj-e0Fw9cWYsf2jCQVEiUsydVkg&amp;pvsid=1596426275047371&amp;tmod=465429636&amp;uas=0&amp;nvt=1&amp;ref=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Fwp-admin%2Fpost.php%3Fpost%3D1713%26action%3Dedit&amp;fc=1408&amp;brdim=0%2C0%2C0%2C0%2C1366%2C0%2C1366%2C720%2C1707%2C791&amp;vis=1&amp;rsz=%7C%7Cs%7C&amp;abl=NS&amp;fu=128&amp;bc=31&amp;bz=0.8&amp;td=1&amp;tdf=0&amp;psd=W251bGwsbnVsbCxudWxsLDNd&amp;nt=1&amp;ifi=13&amp;uci=a!d&amp;btvi=6&amp;fsb=1&amp;dtd=1592\" name=\"aswift_12\" width=\"890\" height=\"0\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" sandbox=\"allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation\" data-google-container-id=\"a!d\" aria-label=\"Advertisement\" data-google-query-id=\"CNL5-brqzIkDFZFNuAQd7GcX7w\" data-load-complete=\"true\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<p><b>b) Which equipment consumes the most energy?<\/b><\/p>\n<div class=\"google-auto-placed ap_container\">\n<p>&nbsp;<\/p>\n<div id=\"aswift_13_host\"><iframe id=\"aswift_13\" tabindex=\"0\" title=\"Advertisement\" src=\"https:\/\/googleads.g.doubleclick.net\/pagead\/ads?gdpr=0&amp;us_privacy=1---&amp;gpp_sid=-1&amp;client=ca-pub-4904230854272924&amp;output=html&amp;h=280&amp;adk=2572008957&amp;adf=883557129&amp;w=890&amp;abgtt=7&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1731072196&amp;num_ads=1&amp;rafmt=1&amp;armr=3&amp;sem=mc&amp;pwprc=4065565381&amp;ad_type=text_image&amp;format=890x280&amp;url=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Feletricidade%2Feletrodinamica%2Fpotencia-eletrica-energia-eletrica%2Fexercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica%2F&amp;host=ca-host-pub-2644536267352236&amp;fwr=0&amp;pra=3&amp;rh=200&amp;rw=890&amp;rpe=1&amp;resp_fmts=3&amp;wgl=1&amp;fa=27&amp;uach=WyJXaW5kb3dzIiwiMTUuMC4wIiwieDg2IiwiIiwiMTIwLjAuNjA5OS43MiIsbnVsbCwwLG51bGwsIjY0IixbWyJOb3RfQSBCcmFuZCIsIjguMC4wLjAiXSxbIkNocm9taXVtIiwiMTIwLjAuNjA5OS43MiJdLFsiR29vZ2xlIENocm9tZSIsIjEyMC4wLjYwOTkuNzIiXV0sMF0.&amp;dt=1731072194557&amp;bpp=4&amp;bdt=5308&amp;idt=-M&amp;shv=r20241106&amp;mjsv=m202410310101&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D2fc0e8f762635b59%3AT%3D1724070743%3ART%3D1731072191%3AS%3DALNI_MY5o0gCt1iJgGxp5gzyTHQ01LNs_Q&amp;eo_id_str=ID%3D1d14c7920cc7842b%3AT%3D1724070743%3ART%3D1731072191%3AS%3DAA-AfjaSoQ0jWyJl98idd6reyYjh&amp;prev_fmts=0x0%2C1200x280%2C300x600%2C300x600%2C300x600%2C890x280%2C890x280%2C890x280&amp;nras=6&amp;correlator=7304014780565&amp;frm=20&amp;pv=1&amp;u_tz=-180&amp;u_his=50&amp;u_h=768&amp;u_w=1366&amp;u_ah=720&amp;u_aw=1366&amp;u_cd=24&amp;u_sd=0.8&amp;dmc=4&amp;adx=199&amp;ady=1949&amp;biw=1686&amp;bih=791&amp;scr_x=0&amp;scr_y=0&amp;eid=44759876%2C44759927%2C95346097%2C31088670%2C95343682%2C95344188%2C95344787%2C31088698%2C95335247%2C31088457%2C95345967%2C95347174&amp;oid=2&amp;psts=AOrYGsk88sw7EJcr2uB8As1vMD-C_UjLH8EnwtDwkfYwYjWHhn0j41tpPOdcYAMdtaJK96A0pCCTrMeCHlZZxwnFfcGemKdX%2CAOrYGsmMv1HHHKRt2eWIyrm-5ocE1aervc6jtV1VzrsmJICHGZNKSH6BqpHKj-e0Fw9cWYsf2jCQVEiUsydVkg&amp;pvsid=1596426275047371&amp;tmod=465429636&amp;uas=0&amp;nvt=1&amp;ref=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Fwp-admin%2Fpost.php%3Fpost%3D1713%26action%3Dedit&amp;fc=1408&amp;brdim=0%2C0%2C0%2C0%2C1366%2C0%2C1366%2C720%2C1707%2C791&amp;vis=1&amp;rsz=%7C%7Cs%7C&amp;abl=NS&amp;fu=128&amp;bc=31&amp;bz=0.8&amp;td=1&amp;tdf=0&amp;psd=W251bGwsbnVsbCxudWxsLDNd&amp;nt=1&amp;ifi=14&amp;uci=a!e&amp;btvi=7&amp;fsb=1&amp;dtd=1622\" name=\"aswift_13\" width=\"890\" height=\"0\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" sandbox=\"allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation\" data-google-container-id=\"a!e\" aria-label=\"Advertisement\" data-google-query-id=\"CIOl-rrqzIkDFT1KuAQdZygq2w\" data-load-complete=\"true\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<p><b>c) Place the five devices in ascending order of energy consumption.<\/b><\/p>\n<div class=\"google-auto-placed ap_container\">\n<p>&nbsp;<\/p>\n<div id=\"aswift_14_host\"><iframe id=\"aswift_14\" tabindex=\"0\" title=\"Advertisement\" src=\"https:\/\/googleads.g.doubleclick.net\/pagead\/ads?gdpr=0&amp;us_privacy=1---&amp;gpp_sid=-1&amp;client=ca-pub-4904230854272924&amp;output=html&amp;h=280&amp;adk=2572008957&amp;adf=3152933139&amp;w=890&amp;abgtt=7&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1731072196&amp;num_ads=1&amp;rafmt=1&amp;armr=3&amp;sem=mc&amp;pwprc=4065565381&amp;ad_type=text_image&amp;format=890x280&amp;url=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Feletricidade%2Feletrodinamica%2Fpotencia-eletrica-energia-eletrica%2Fexercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica%2F&amp;host=ca-host-pub-2644536267352236&amp;fwr=0&amp;pra=3&amp;rh=200&amp;rw=890&amp;rpe=1&amp;resp_fmts=3&amp;wgl=1&amp;fa=27&amp;uach=WyJXaW5kb3dzIiwiMTUuMC4wIiwieDg2IiwiIiwiMTIwLjAuNjA5OS43MiIsbnVsbCwwLG51bGwsIjY0IixbWyJOb3RfQSBCcmFuZCIsIjguMC4wLjAiXSxbIkNocm9taXVtIiwiMTIwLjAuNjA5OS43MiJdLFsiR29vZ2xlIENocm9tZSIsIjEyMC4wLjYwOTkuNzIiXV0sMF0.&amp;dt=1731072194557&amp;bpp=11&amp;bdt=5307&amp;idt=-M&amp;shv=r20241106&amp;mjsv=m202410310101&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D2fc0e8f762635b59%3AT%3D1724070743%3ART%3D1731072191%3AS%3DALNI_MY5o0gCt1iJgGxp5gzyTHQ01LNs_Q&amp;eo_id_str=ID%3D1d14c7920cc7842b%3AT%3D1724070743%3ART%3D1731072191%3AS%3DAA-AfjaSoQ0jWyJl98idd6reyYjh&amp;prev_fmts=0x0%2C1200x280%2C300x600%2C300x600%2C300x600%2C890x280%2C890x280%2C890x280%2C890x280&amp;nras=7&amp;correlator=7304014780565&amp;frm=20&amp;pv=1&amp;u_tz=-180&amp;u_his=50&amp;u_h=768&amp;u_w=1366&amp;u_ah=720&amp;u_aw=1366&amp;u_cd=24&amp;u_sd=0.8&amp;dmc=4&amp;adx=199&amp;ady=2280&amp;biw=1686&amp;bih=791&amp;scr_x=0&amp;scr_y=0&amp;eid=44759876%2C44759927%2C95346097%2C31088670%2C95343682%2C95344188%2C95344787%2C31088698%2C95335247%2C31088457%2C95345967%2C95347174&amp;oid=2&amp;psts=AOrYGsk88sw7EJcr2uB8As1vMD-C_UjLH8EnwtDwkfYwYjWHhn0j41tpPOdcYAMdtaJK96A0pCCTrMeCHlZZxwnFfcGemKdX%2CAOrYGsmMv1HHHKRt2eWIyrm-5ocE1aervc6jtV1VzrsmJICHGZNKSH6BqpHKj-e0Fw9cWYsf2jCQVEiUsydVkg&amp;pvsid=1596426275047371&amp;tmod=465429636&amp;uas=0&amp;nvt=1&amp;ref=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Fwp-admin%2Fpost.php%3Fpost%3D1713%26action%3Dedit&amp;fc=1408&amp;brdim=0%2C0%2C0%2C0%2C1366%2C0%2C1366%2C720%2C1707%2C791&amp;vis=1&amp;rsz=%7C%7Cs%7C&amp;abl=NS&amp;fu=128&amp;bc=31&amp;bz=0.8&amp;td=1&amp;tdf=0&amp;psd=W251bGwsbnVsbCxudWxsLDNd&amp;nt=1&amp;ifi=15&amp;uci=a!f&amp;btvi=8&amp;fsb=1&amp;dtd=1681\" name=\"aswift_14\" width=\"890\" height=\"0\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" sandbox=\"allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation\" data-google-container-id=\"a!f\" aria-label=\"Advertisement\" data-google-query-id=\"CJ-E-rrqzIkDFWhMuAQdqJUBtA\" data-load-complete=\"true\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<p><b>02-(ENEM-MEC)<\/b><b>\u00a0The average distribution, by type of equipment, of electricity consumption in homes in Brazil is shown in the graph.<\/b><\/p>\n<div class=\"google-auto-placed ap_container\">\n<p>&nbsp;<\/p>\n<div id=\"aswift_15_host\"><iframe id=\"aswift_15\" tabindex=\"0\" title=\"Advertisement\" src=\"https:\/\/googleads.g.doubleclick.net\/pagead\/ads?gdpr=0&amp;us_privacy=1---&amp;gpp_sid=-1&amp;client=ca-pub-4904230854272924&amp;output=html&amp;h=280&amp;adk=2572008957&amp;adf=26626011&amp;w=890&amp;abgtt=7&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1731072196&amp;num_ads=1&amp;rafmt=1&amp;armr=3&amp;sem=mc&amp;pwprc=4065565381&amp;ad_type=text_image&amp;format=890x280&amp;url=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Feletricidade%2Feletrodinamica%2Fpotencia-eletrica-energia-eletrica%2Fexercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica%2F&amp;host=ca-host-pub-2644536267352236&amp;fwr=0&amp;pra=3&amp;rh=200&amp;rw=890&amp;rpe=1&amp;resp_fmts=3&amp;wgl=1&amp;fa=27&amp;uach=WyJXaW5kb3dzIiwiMTUuMC4wIiwieDg2IiwiIiwiMTIwLjAuNjA5OS43MiIsbnVsbCwwLG51bGwsIjY0IixbWyJOb3RfQSBCcmFuZCIsIjguMC4wLjAiXSxbIkNocm9taXVtIiwiMTIwLjAuNjA5OS43MiJdLFsiR29vZ2xlIENocm9tZSIsIjEyMC4wLjYwOTkuNzIiXV0sMF0.&amp;dt=1731072194557&amp;bpp=4&amp;bdt=5308&amp;idt=-M&amp;shv=r20241106&amp;mjsv=m202410310101&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D2fc0e8f762635b59%3AT%3D1724070743%3ART%3D1731072191%3AS%3DALNI_MY5o0gCt1iJgGxp5gzyTHQ01LNs_Q&amp;eo_id_str=ID%3D1d14c7920cc7842b%3AT%3D1724070743%3ART%3D1731072191%3AS%3DAA-AfjaSoQ0jWyJl98idd6reyYjh&amp;prev_fmts=0x0%2C1200x280%2C300x600%2C300x600%2C300x600%2C890x280%2C890x280%2C890x280%2C890x280%2C890x280&amp;nras=8&amp;correlator=7304014780565&amp;frm=20&amp;pv=1&amp;u_tz=-180&amp;u_his=50&amp;u_h=768&amp;u_w=1366&amp;u_ah=720&amp;u_aw=1366&amp;u_cd=24&amp;u_sd=0.8&amp;dmc=4&amp;adx=199&amp;ady=2638&amp;biw=1686&amp;bih=791&amp;scr_x=0&amp;scr_y=0&amp;eid=44759876%2C44759927%2C95346097%2C31088670%2C95343682%2C95344188%2C95344787%2C31088698%2C95335247%2C31088457%2C95345967%2C95347174&amp;oid=2&amp;psts=AOrYGsk88sw7EJcr2uB8As1vMD-C_UjLH8EnwtDwkfYwYjWHhn0j41tpPOdcYAMdtaJK96A0pCCTrMeCHlZZxwnFfcGemKdX%2CAOrYGsmMv1HHHKRt2eWIyrm-5ocE1aervc6jtV1VzrsmJICHGZNKSH6BqpHKj-e0Fw9cWYsf2jCQVEiUsydVkg&amp;pvsid=1596426275047371&amp;tmod=465429636&amp;uas=0&amp;nvt=1&amp;ref=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Fwp-admin%2Fpost.php%3Fpost%3D1713%26action%3Dedit&amp;fc=1408&amp;brdim=0%2C0%2C0%2C0%2C1366%2C0%2C1366%2C720%2C1707%2C791&amp;vis=1&amp;rsz=%7C%7Cs%7C&amp;abl=NS&amp;cms=2&amp;fu=128&amp;bc=31&amp;bz=0.8&amp;td=1&amp;tdf=0&amp;psd=W251bGwsbnVsbCxudWxsLDNd&amp;nt=1&amp;ifi=16&amp;uci=a!g&amp;btvi=9&amp;fsb=1&amp;dtd=1725\" name=\"aswift_15\" width=\"890\" height=\"0\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" sandbox=\"allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation\" data-google-container-id=\"a!g\" aria-label=\"Advertisement\" data-google-query-id=\"CJaU-rrqzIkDFXxauAQdTkkBMQ\" data-load-complete=\"true\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_c600a233.jpg\" alt=\"\" width=\"343\" height=\"111\" name=\"graphics10\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>In association with the graph data, consider the variables:<\/b><\/p>\n<div class=\"google-auto-placed ap_container\">\n<p>&nbsp;<\/p>\n<div id=\"aswift_16_host\"><iframe id=\"aswift_16\" tabindex=\"0\" title=\"Advertisement\" src=\"https:\/\/googleads.g.doubleclick.net\/pagead\/ads?gdpr=0&amp;us_privacy=1---&amp;gpp_sid=-1&amp;client=ca-pub-4904230854272924&amp;output=html&amp;h=280&amp;adk=2572008957&amp;adf=1997250411&amp;w=890&amp;abgtt=7&amp;fwrn=4&amp;fwrnh=100&amp;lmt=1731072196&amp;num_ads=1&amp;rafmt=1&amp;armr=3&amp;sem=mc&amp;pwprc=4065565381&amp;ad_type=text_image&amp;format=890x280&amp;url=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Feletricidade%2Feletrodinamica%2Fpotencia-eletrica-energia-eletrica%2Fexercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica%2F&amp;host=ca-host-pub-2644536267352236&amp;fwr=0&amp;pra=3&amp;rh=200&amp;rw=890&amp;rpe=1&amp;resp_fmts=3&amp;wgl=1&amp;fa=27&amp;uach=WyJXaW5kb3dzIiwiMTUuMC4wIiwieDg2IiwiIiwiMTIwLjAuNjA5OS43MiIsbnVsbCwwLG51bGwsIjY0IixbWyJOb3RfQSBCcmFuZCIsIjguMC4wLjAiXSxbIkNocm9taXVtIiwiMTIwLjAuNjA5OS43MiJdLFsiR29vZ2xlIENocm9tZSIsIjEyMC4wLjYwOTkuNzIiXV0sMF0.&amp;dt=1731072194557&amp;bpp=3&amp;bdt=5307&amp;idt=3&amp;shv=r20241106&amp;mjsv=m202410310101&amp;ptt=9&amp;saldr=aa&amp;abxe=1&amp;cookie=ID%3D2fc0e8f762635b59%3AT%3D1724070743%3ART%3D1731072191%3AS%3DALNI_MY5o0gCt1iJgGxp5gzyTHQ01LNs_Q&amp;eo_id_str=ID%3D1d14c7920cc7842b%3AT%3D1724070743%3ART%3D1731072191%3AS%3DAA-AfjaSoQ0jWyJl98idd6reyYjh&amp;prev_fmts=0x0%2C1200x280%2C300x600%2C300x600%2C300x600%2C890x280%2C890x280%2C890x280%2C890x280%2C890x280%2C890x280&amp;nras=9&amp;correlator=7304014780565&amp;frm=20&amp;pv=1&amp;u_tz=-180&amp;u_his=50&amp;u_h=768&amp;u_w=1366&amp;u_ah=720&amp;u_aw=1366&amp;u_cd=24&amp;u_sd=0.8&amp;dmc=4&amp;adx=199&amp;ady=3109&amp;biw=1686&amp;bih=791&amp;scr_x=0&amp;scr_y=0&amp;eid=44759876%2C44759927%2C95346097%2C31088670%2C95343682%2C95344188%2C95344787%2C31088698%2C95335247%2C31088457%2C95345967%2C95347174&amp;oid=2&amp;psts=AOrYGsk88sw7EJcr2uB8As1vMD-C_UjLH8EnwtDwkfYwYjWHhn0j41tpPOdcYAMdtaJK96A0pCCTrMeCHlZZxwnFfcGemKdX%2CAOrYGsmMv1HHHKRt2eWIyrm-5ocE1aervc6jtV1VzrsmJICHGZNKSH6BqpHKj-e0Fw9cWYsf2jCQVEiUsydVkg&amp;pvsid=1596426275047371&amp;tmod=465429636&amp;uas=0&amp;nvt=1&amp;ref=https%3A%2F%2Ffisicaevestibular.com.br%2Fnovo%2Fwp-admin%2Fpost.php%3Fpost%3D1713%26action%3Dedit&amp;fc=1408&amp;brdim=0%2C0%2C0%2C0%2C1366%2C0%2C1366%2C720%2C1707%2C791&amp;vis=1&amp;rsz=%7C%7Cs%7C&amp;abl=NS&amp;fu=128&amp;bc=31&amp;bz=0.8&amp;td=1&amp;tdf=0&amp;psd=W251bGwsbnVsbCxudWxsLDNd&amp;nt=1&amp;ifi=17&amp;uci=a!h&amp;btvi=10&amp;fsb=1&amp;dtd=1813\" name=\"aswift_16\" width=\"890\" height=\"0\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\" sandbox=\"allow-forms allow-popups allow-popups-to-escape-sandbox allow-same-origin allow-scripts allow-top-navigation-by-user-activation\" data-google-container-id=\"a!h\" aria-label=\"Advertisement\" data-google-query-id=\"CMGY-rrqzIkDFfFKuAQduBgROA\" data-load-complete=\"true\" data-mce-fragment=\"1\"><\/iframe><\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<p><b>I. Equipment power.<\/b><\/p>\n<p><b>II. Hours of operation.<\/b><\/p>\n<p><b>III. Number of equipment.<\/b><\/p>\n<p><b>The value of the percentage fractions of energy consumption depends on<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_170d2e24.png\" alt=\"\" width=\"774\" height=\"20\" name=\"Imagem 188\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>03-(ENEM-MEC)<\/b><b>\u00a0Among the numerous recommendations given for saving electricity in a home, we highlight the following:<\/b><\/p>\n<p><b>\u2013 Replace incandescent light bulbs with compact fluorescent ones.- Avoid using the electric shower with the switch in the \u201cwinter\u201d or \u201chot\u201d position.<\/b><\/p>\n<p><b>\u2013 Accumulate a quantity of clothes to be ironed with an electric iron at once.<\/b><\/p>\n<p><b>\u2013 Avoid using multiple sockets to connect several devices simultaneously.<\/b><\/p>\n<p><b>\u2013 Use wires with diameters recommended for their intended purpose in the electrical installation.<\/b><\/p>\n<p><b>The common feature of all these recommendations is the proposal to save energy by trying to reduce, on a daily basis,<\/b><\/p>\n<p><b>a) the power of electrical appliances and devices.<\/b><\/p>\n<p><b>b) the time of use of the devices and appliances.<\/b><\/p>\n<p><b>c) the consumption of electrical energy converted into thermal energy.<\/b><\/p>\n<p><b>d) the consumption of thermal energy converted into electrical energy.<\/b><\/p>\n<p><b>e) the consumption of electrical energy through leakage currents.<\/b><\/p>\n<p><b>04-(ENEM-MEC)<\/b><b>\u00a0\u201c\u2026Brazil has the potential to produce at least 15 thousand megawatts per hour of energy from alternative sources\u201d.<\/b><\/p>\n<p><b>In the southern states alone, the potential for generating energy through agricultural and forestry waste is 5,000 megawatts per hour.<\/b><\/p>\n<p><b>To get an idea of \u200b\u200bwhat this represents, the Ita hydroelectric plant, one of the largest in the country, on the border between Rio Grande do Sul and Santa Catarina, generates 1,450 megawatts of energy per hour.\u201d<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_a04d651e.jpg\" alt=\"\" width=\"368\" height=\"126\" name=\"graphics11\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>This text, transcribed from a widely circulated newspaper, contains at least ONE CONCEPTUAL ERROR when presenting production values \u200b\u200band energy generation potential. This error consists of<\/b><\/p>\n<p><b>a) present very high values \u200b\u200bfor the energy quantity.<\/b><\/p>\n<p><b>b) use the megawatt unit to express power values.<\/b><\/p>\n<p><b>c) use electric units for biomass.<\/b><\/p>\n<p><b>d) using the incorrect unit megawatt per hour.<\/b><\/p>\n<p><b>e) present numerical values \u200b\u200bincompatible with the units.<\/b><\/p>\n<p><b>05-(UNICAMP-SP)<\/b><b>\u00a0A circuit breaker is an electrical protection switch that turns off the circuit when the current exceeds a certain value.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_386a0c12.jpg\" alt=\"\" width=\"116\" height=\"140\" name=\"Imagem 13\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>The 110V electrical network of a house is protected by a 15A circuit breaker. The following equipment is available: a 2,200W\u00a0<a class=\"google-anno\" href=\"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica\/#\" data-google-vignette=\"false\" data-google-interstitial=\"false\">\u00a0<span class=\"google-anno-t\">water<\/span><\/a>\u00a0heater , a 770W iron and 100W light bulbs.<\/b><\/p>\n<p><b>a) Which of these devices can be connected to the electrical grid, one at a time, without turning off the circuit breaker?<\/b><\/p>\n<p><b>b) If only 100W lamps are connected to the electrical network, what is the maximum number of these lamps that can be connected simultaneously without turning off the 15A circuit breaker?<\/b><\/p>\n<p><b>06-(UFPE-PE)<\/b><b>\u00a0A special lamp has a current versus potential difference curve as shown in the figure.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_3a6c31e1.jpg\" alt=\"\" width=\"345\" height=\"136\" name=\"Imagem 14\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>What power will be dissipated, in watts, in the lamp when it is subjected to a potential difference of 10V? 2W<\/b><\/p>\n<p><b>07-(PUCCAMP-SP)<\/b><b>\u00a0The electric eel, or poraqu\u00ea, a freshwater fish from the Amazon region, can reach 2.5 m in length and 25 cm in diameter. Its voltage source \u2013 the electroplates \u2013 is located in its tail, which occupies about four fifths of its length.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_741e19f7.jpg\" alt=\"\" width=\"411\" height=\"101\" name=\"Imagem 15\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>Depending on the size and vitality of the animal, these electroplates can generate a voltage of 600V and a current of 2.0A, in pulses lasting about 3.0 thousandths of a second, a discharge sufficient to stun a person or kill small animals.<\/b><\/p>\n<p><b>(Adapted from Alberto Gaspar. \u201cPhysics\u201d. v.3. S\u00e3o Paulo: \u00c1tica, 2000, p. 135)<\/b><\/p>\n<p><b>The electrical energy that the eel generates, in each pulse, in joules, is:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_72237ec1.png\" alt=\"\" width=\"774\" height=\"19\" name=\"Imagem 189\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>08-(UFU-MG)<\/b><b>\u00a0Two irons consume the same power. The first was designed to be used at a voltage of 110 V, while the second for a voltage of 220 V.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_d2fc533d.jpg\" alt=\"\" width=\"140\" height=\"92\" name=\"Imagem 16\" align=\"BOTTOM\" border=\"0\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_19d4cd55.jpg\" alt=\"\" width=\"138\" height=\"94\" name=\"Imagem 17\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>Under the designed conditions of use of the irons, it is correct to state that:<\/b><\/p>\n<p><b>a) the energy consumption will be greater for the first iron, and the current that will flow through the first will be greater than the current that will flow through the second iron.<\/b><\/p>\n<p><b>b) the energy consumption will be the same for both irons, and the current that will flow through the first will be greater than the current that will flow through the second iron.<\/b><\/p>\n<p><b>c) the energy consumption will be greater for the second iron, and the electric currents that will run through each iron will be the same.<\/b><\/p>\n<p><b>d) the energy consumption will be the same for both irons and the electric currents that will run through each iron will also be the same.<\/b><\/p>\n<p><b>09-(UNIFESP-SP)<\/b><b>\u00a0According to a manufacturer, a fluorescent lamp whose nominal values<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_84179507.jpg\" alt=\"\" width=\"127\" height=\"77\" name=\"Imagem 18\" align=\"BOTTOM\" border=\"0\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_d0b81139.jpg\" alt=\"\" width=\"133\" height=\"80\" name=\"Imagem 19\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>are 11W \/ 127V equivalent to an incandescent bulb with nominal values \u200b\u200bof 40W \/ 127V. This information means that<\/b><\/p>\n<p><b>a) both dissipate the same power and produce the same luminosity.<\/b><\/p>\n<p><b>b) both dissipate the same power, but the brightness of the fluorescent lamp is greater.<\/b><\/p>\n<p><b>c) both dissipate the same power, but the brightness of the incandescent lamp is greater.<\/b><\/p>\n<p><b>d) the incandescent lamp produces the same brightness as the fluorescent lamp, dissipating less power.<\/b><\/p>\n<p><b>e) the fluorescent lamp produces the same brightness as the incandescent lamp, dissipating less power.<\/b><\/p>\n<p><b>10-(UNESP-SP)<\/b><b>\u00a0A cell phone charger, which can be connected to the cigarette lighter outlet.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_f2505963.jpg\" alt=\"\" width=\"191\" height=\"113\" name=\"Imagem 20\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>A car, sold on the streets of S\u00e3o Paulo, bears the following inscription:<\/b><\/p>\n<p><b>SUPPLY VOLTAGE; 24W<\/b><\/p>\n<p><b>POWER CONSUMPTION: 150V<\/b><\/p>\n<p><b>This instruction was written by a manufacturer with good practical knowledge, but careless about the meaning and correct use of the SI (International System) units adopted in Brazil.<\/b><\/p>\n<p><b>a) Rewrite the instruction, correctly using the SI units of measurement.<\/b><\/p>\n<p><b>b) Calculate the intensity of the electric current used by the device.<\/b><\/p>\n<p><b>11-(ENEM-MEC)<\/b><b>\u00a0We can estimate the electricity consumption of a house by considering the main sources of this consumption. Think about the situation in which only the appliances listed in the following table were used daily in the same way.<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_4fec015d.jpg\" alt=\"\" width=\"765\" height=\"137\" name=\"Imagem 21\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Table: The table provides the power and effective daily usage time of each household appliance.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_6fbdc5f6.jpg\" alt=\"\" width=\"335\" height=\"129\" name=\"Imagem 22\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Assuming that the month has 30 days and that the cost of 1kWh is R$ 0.40, the monthly electricity consumption of this house is approximately<\/b><\/p>\n<p><b>a) R$ 135.<\/b><\/p>\n<p><b>b) R$ 165.<\/b><\/p>\n<p><b>c) R$ 190.<\/b><\/p>\n<p><b>d) R$ 210.<\/b><\/p>\n<p><b>e) R$ 230.<\/b><\/p>\n<p><b>12-(UERJ-RJ)<\/b><b>\u00a04,000 60 W lamps and 600 120 W lamps are used to light the ship.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_841de0d6.jpg\" alt=\"\" width=\"336\" height=\"125\" name=\"Imagem 23\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>200 W, all subjected to an effective voltage of 120 V, which remain on, on average, 12 hours a day.<\/b><\/p>\n<p><b>Considering this data, determine:<\/b><\/p>\n<p><b>a) the total electric current required to keep them lit;<\/b><\/p>\n<p><b>b) the approximate cost, in reais, of the energy they consumed on a 10-day trip, knowing that the cost of kWh is R$ 0.40.<\/b><\/p>\n<p><b>13-(UNIFESP-SP)<\/b><b>\u00a0Currently, most electronic devices, even when turned off, remain in \u201cstandby\u201d, an English word that in this case means \u201cready to use\u201d. Keeping the equipment in this operating mode reduces the time needed for it to return to operation and prevents wear and tear on the internal circuits due to voltage spikes that appear the moment it is turned on. In other words, a device in this condition is always partially on and, therefore, consumes energy. Suppose that a television kept in \u201cstandby\u201d dissipates a power of 12<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_4ab19104.jpg\" alt=\"\" width=\"229\" height=\"170\" name=\"Imagem 24\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>watts and that the cost of a kilowatt-hour is R$0.50. If it is kept on \u201cstandby\u201d for a year (assume 1 year = 8,800 hours), its energy consumption will be approximately<\/b><\/p>\n<p><b>a) R$ 1.00.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) R$ 10.00.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) R$ 25.00.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) R$50.00.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>e) R$ 200.00.<\/b><\/p>\n<p><b>14-(UERJ-RJ)<\/b><b>\u00a0A group of students, when observing a storm, imagined what the value would be, in reais, of the electrical energy contained in the lightning.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_f4bbc4dd.jpg\" alt=\"\" width=\"314\" height=\"131\" name=\"Imagem 25\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>To define this value, the following data were considered:<\/b><\/p>\n<p><b>\u2013 average electric potential of lightning = 2.5 \u00d7 10\u00a0<\/b><sup><b>7<\/b><\/sup><b>\u00a0V;<\/b><b>\u00a0<\/b><b><\/b><\/p>\n<p><b>\u2013 intensity of the established electric current = 2.0 \u00d7 10\u00a0<\/b><sup><b>5<\/b><\/sup><b>\u00a0A;<\/b><b>\u00a0<\/b><b><\/b><\/p>\n<p><b>\u2013 cost of 1 kWh = R$ 0.38.<\/b><\/p>\n<p><b>\u2013 1kWh\u00a0<\/b><b>=\u00a0<\/b><sup><b>3.6.106J<\/b><\/sup><b><\/b><\/p>\n<p><b>Assuming that lightning lasts for one thousandth of a second, the approximate value in reais, calculated by the group for the energy contained in it, is equivalent to:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_34f63739.png\" alt=\"\" width=\"774\" height=\"19\" name=\"Imagem 190\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>15- (FUVEST-SP)<\/b><b>\u00a0The graph shows the variation of the effective current, in amperes, of an electric heater that operated under an effective voltage of 120V, for 400 minutes.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_913a7cfe.jpg\" alt=\"\" width=\"266\" height=\"138\" name=\"Imagem 26\" align=\"BOTTOM\" border=\"0\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_26f41a90.jpg\" alt=\"\" width=\"324\" height=\"146\" name=\"Imagem 27\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>a) If the cost of electricity is C$0.20 per kilowatt-hour, determine the cost of the energy supplied to the heater during the indicated 400 minutes.<\/b><\/p>\n<p><b>b) If 1\/3 of the total energy transferred to the heater, in the first 42 minutes of operation, was used to heat 10 liters of\u00a0<a class=\"google-anno\" href=\"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica\/#\" data-google-vignette=\"false\" data-google-interstitial=\"false\">\u00a0<span class=\"google-anno-t\">water<\/span><\/a>\u00a0, determine the variation in water temperature. Consider: specific heat of water c = 4.2.103\u00a0<\/b><sup><b>kg<\/b><\/sup><b>\u00a0\/J and that the volume of 1L of water has a mass of 1kg and 1kWh =\u00a0<\/b><sup><b>3.6.106<\/b><\/sup><b>\u00a0J.<\/b><\/p>\n<p><b>16-(UFRS-RS)<\/b><b>\u00a0To light their tent, a group of campers connect a lamp to a car battery.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_58650a1e.jpg\" alt=\"\" width=\"395\" height=\"129\" name=\"graphics12\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>The lamp consumes 6 W of power when operating at a voltage of 12 V. The battery has the following specifications: 12 V, 45 Ah, with the last value being the maximum charge that the battery can store. Assuming that the battery is ideal and that it is at half its maximum charge, and assuming that the current supplied by it remains constant until the charge is completely depleted, how many hours can the lamp remain in continuous operation?<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_d5323b22.png\" alt=\"\" width=\"774\" height=\"20\" name=\"Imagem 191\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>17-(UFMS-MS)<\/b><b>\u00a0Solar energy is one of the alternative energy sources used by man. The average annual intensity of solar radiation in the city of Campo Grande &#8211; MS is equal to 700 W\/m2\u00a0<\/b><sup><b>considering<\/b><\/sup><b>\u00a06 hours of irradiation per day.<\/b><b>\u00a0<\/b><b><\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_45edcf3b.jpg\" alt=\"\" width=\"262\" height=\"164\" name=\"Imagem 29\" align=\"BOTTOM\" border=\"0\" \/><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_27b389f1.jpg\" alt=\"\" width=\"442\" height=\"169\" name=\"Imagem 30\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>A solar energy capture device to heat water for domestic consumption has a yield equal to 60%, that is, 60% of the available solar radiation power is transformed into useful power by the device. Consider a residence that has one of these devices installed, whose solar radiation capture area is 4 m2\u00a0<\/b><sup><b>and<\/b><\/sup><b>\u00a0all useful power is consumed. If the cost of electricity in the location is R$0.60 per kWh, the average annual savings (365 days) in reais, in this residence, will be<\/b><b>\u00a0<\/b><b><\/b><\/p>\n<p><b>a) greater than R$2,124.00.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) equal to R$551.88.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) equal to R$ 367.92.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) less than R$367.92.<\/b><\/p>\n<p><b>e) equal to R$ 1,980.00.<\/b><\/p>\n<p><b>18-(UNIFESP-SP)<\/b><b>\u00a0A consumer exchanges his 29-inch, 70 W television for a 42-inch, 220 W plasma television.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_2bebae51.jpg\" alt=\"\" width=\"322\" height=\"160\" name=\"Imagem 31\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>If you watch television for an average of 6 hours a day at home, it can be said that the increase in monthly electricity consumption that this change will entail is approximately<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_66902f20.png\" alt=\"\" width=\"774\" height=\"17\" name=\"Imagem 192\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>19-(FUVEST-SP)<\/b><b>\u00a0In most homes that have cable TV systems, the device that decodes the signal remains on without interruption, operating with a power of approximately 6 W, even when the TV is not on.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_a73f0546.jpg\" alt=\"\" width=\"423\" height=\"149\" name=\"graphics13\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>The energy consumption of the decoder, during one month (30 days), would be equivalent to that of a 60 W light bulb that remained on, without interruption, for<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_4e9cd473.png\" alt=\"\" width=\"775\" height=\"19\" name=\"Imagem 193\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>20-(UFG-GO)<\/b><b>\u00a0In Ecuador, the average solar radiation, per month, on the Earth&#8217;s surface, is approximately 792 MJ\/m2\u00a0<\/b><sup><b>.<\/b><\/sup><b>\u00a0For approximately how many hours must a heater with a voltage equal to 220 V and an electric current of 20 A remain on to produce an amount of heat equivalent to the monthly solar energy incident on 1.00\u00a0<\/b><sup><b>m2<\/b><\/sup><b>\u00a0?<\/b><\/p>\n<p><b>a) 3 hours<\/b><b>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><b>\u00a0<\/b><\/p>\n<p><b>b) 20 hours<\/b><b>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><b>\u00a0<\/b><\/p>\n<p><b>c) 50 hours<\/b><b>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><b>\u00a0<\/b><\/p>\n<p><b>d) 250 hours<\/b><b>\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><b>\u00a0<\/b><\/p>\n<p><b>e) 1000 hours<\/b><\/p>\n<p><b>21-(UFG-GO)<\/b><b>\u00a0A cell phone operates in a frequency range of 824 Hz to 849 MHz. The charges and battery life of 6V batteries for this type of phone are given in the following table.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_5f714b86.jpg\" alt=\"\" width=\"513\" height=\"110\" name=\"Imagem 33\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>a) Knowing that the speed of an electromagnetic wave in air is approximately 3.10\u00a0<\/b><sup><b>8<\/b><\/sup><b>\u00a0m\/s, what is the approximate wavelength for the frequency of 830 MHz?<\/b><\/p>\n<p><b>b) How much charge (in coulombs) is supplied by the 0.80Ah battery?<\/b><\/p>\n<p><b>c) Calculate the electric current and average power supplied by the 0.80Ah battery.<\/b><\/p>\n<p><b>22-(FUVEST-SP)<\/b><b>\u00a0Fluorescent lamps provide much more light than incandescent lamps of the same power. In compact fluorescent lamps (socket lamps), the luminous efficiency, measured in lumens per watt (lm\/W), is around 60 lm\/W, and in incandescent lamps, it is around 15 lm\/W. In a residence, 10 100 W incandescent lamps are replaced by compact fluorescent lamps that provide equivalent lighting (the same amount of lumens). Assuming that the lamps are on for an average of 6 hours per day and that the price of electricity is R$0.30 per kWh, the monthly savings on the electricity bill for this residence will be approximately:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_e9e371b7.png\" alt=\"\" width=\"774\" height=\"17\" name=\"Imagem 194\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>23-(PUC-SP)<\/b><b>\u00a0An immersion heater (boiler) dissipates 200W of power, fully utilized<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8edfa85a.jpg\" alt=\"\" width=\"314\" height=\"148\" name=\"Imagem 34\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>to heat 100g of\u00a0<a class=\"google-anno\" href=\"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica\/#\" data-google-vignette=\"false\" data-google-interstitial=\"false\">\u00a0<span class=\"google-anno-t\">water<\/span><\/a>\u00a0for 1 minute. What is the temperature variation experienced by the water?<\/b><\/p>\n<p><b>Consider: 1cal=4J and\u00a0<\/b><sub><b>water<\/b><\/sub><b>\u00a0=1cal\/g\u00a0<\/b><sup><b>o<\/b><\/sup><b>\u00a0C<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_18069efb.png\" alt=\"\" width=\"774\" height=\"18\" name=\"Imagem 195\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>24-(FUVEST-SP)<\/b><b>\u00a0In most homes that have cable TV systems, the device that decodes the signal remains on without interruption, operating with a power of approximately 6 W, even when the TV is not on.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_5ed18847.jpg\" alt=\"\" width=\"348\" height=\"175\" name=\"Imagem 35\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>The energy consumption of the decoder, during one month (30 days), would be equivalent to that of a 60 W light bulb that remained on, without interruption, for<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_ed5703bf.png\" alt=\"\" width=\"774\" height=\"19\" name=\"Imagem 196\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>25-(ITA-SP)<\/b><b>\u00a0In 1998, the Itaipu hydroelectric plant supplied approximately 87,600 GWh of electrical energy.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_b0321133.jpg\" alt=\"\" width=\"345\" height=\"156\" name=\"graphics14\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Imagine then a giant photovoltaic panel that can convert into electrical energy, with a yield of 20%, the solar energy incident on the Earth&#8217;s surface, here considered with an average diurnal value (24 h) of approximately 170 W\/\u00a0<\/b><sup><b>m2<\/b><\/sup><b>\u00a0.<\/b><\/p>\n<p><b>Calculate:<\/b><\/p>\n<p><b>a) The horizontal area (in km2\u00a0<\/b><sup><b>)<\/b><\/sup><b>\u00a0occupied by the solar collectors so that the panel can generate, over a year, energy equivalent to that of Itaipu, and,<\/b><\/p>\n<p><b>b) The average percentage at which the plant operated in 1998 in relation to its installed capacity of 14,000 MW.<\/b><\/p>\n<p><b>26-(FUVEST)<\/b><b>\u00a0Fluorescent lamps provide much more light than incandescent lamps of the same power. In compact fluorescent lamps (socket), the luminous efficiency, measured in lumens per watt (lm\/W), is around 60 lm\/W, and in incandescent lamps, it is around 15 lm\/W. In a residence, 10 100 W incandescent lamps are replaced by compact fluorescent lamps that provide equivalent lighting (the same amount of lumens). Assuming that the lamps are on for an average of 6 hours per day and that the price of electricity is R$0.30 per kWh, the monthly savings on the electricity bill for this residence will be approximately:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8e854eae.png\" alt=\"\" width=\"774\" height=\"17\" name=\"Imagem 197\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>27-(UEL-PR)<\/b><b>\u00a0Some modern cars use\u00a0high compression\u00a0<a class=\"google-anno\" href=\"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica\/#\" data-google-vignette=\"false\" data-google-interstitial=\"false\">\u00a0<span class=\"google-anno-t\">engines , which require a lot of power, which only an electric motor can develop.<\/span><\/a><\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_c3ab299a.jpg\" alt=\"\" width=\"292\" height=\"136\" name=\"Imagem 37\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>Typically, a 12-volt battery is used to power the starter motor.<\/b><\/p>\n<p><b>Assuming that this motor draws a current of 400 amps, the power required to start the motor is:<\/b><\/p>\n<p><b>a) 4.0 \u00d7 10\u00a0<\/b><sup><b>2<\/b><\/sup><b>\u00a0W.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><b>\u00a0<\/b><b><\/b><\/p>\n<p><b>b) 4.0 \u00d7 10\u00a0<\/b><sup><b>3<\/b><\/sup><b>\u00a0W.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><b>\u00a0<\/b><b><\/b><\/p>\n<p><b>c) 4.8 \u00d7 10\u00a0<\/b><sup><b>3<\/b><\/sup><b>\u00a0W.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><b>\u00a0<\/b><b><\/b><\/p>\n<p><b>d) 5.76 \u00d7 10\u00a0<\/b><sup><b>4<\/b><\/sup><b>\u00a0W.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>e) 1.92 \u00d710\u00a6 W.<\/b><\/p>\n<p><b>28-(ENEM-MEC)<\/b><b>\u00a0The passage of an adequate amount of electric current through the filament of a light bulb makes it incandescent, producing light. The following graph shows how the intensity of the light emitted by the bulb is distributed across the electromagnetic spectrum, extending from the ultraviolet (UV) region to the infrared region.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_c8ea08c7.jpg\" alt=\"\" width=\"523\" height=\"195\" name=\"Imagem 38\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>The luminous efficiency of a lamp can be defined as the ratio between the amount of energy emitted in the form of visible light and the total amount of energy used for its operation. Assuming that these two quantities can be estimated, respectively, by the area below the part of the curve corresponding to the visible light band and by the area below the entire curve, the luminous efficiency of this lamp would be approximately<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_acab45cb.png\" alt=\"\" width=\"774\" height=\"17\" name=\"Imagem 198\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>29-(ENEM-MEC)<\/b><b>\u00a0The electrical installation of a house involves several stages, from the allocation of electrical devices, instruments and appliances, to the choice of materials that compose it, including the dimensioning of the required power, the necessary wiring, the conduits*, among others.<\/b><\/p>\n<p><b>Each electrical appliance has an associated power value. Typical power values \u200b\u200bfor some appliances are shown in the following table.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_b99a17e6.jpg\" alt=\"\" width=\"469\" height=\"206\" name=\"Imagem 39\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>*Conduits are conduits through which the wiring of an electrical installation passes, with the purpose of protecting it.<\/b><\/p>\n<p><b>The choice of bulbs is essential to obtain good lighting. The power of the bulb should be in accordance with the size of the illuminated room. The following table shows the relationship between the areas of the rooms (in m2\u00a0<\/b><sup><b>)<\/b><\/sup><b>\u00a0and the power of the bulbs (in W), and was used as a reference for the first floor of a residence.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_95db7bd7.jpg\" alt=\"\" width=\"724\" height=\"190\" name=\"Imagem 40\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Note: For the purposes of calculating areas, walls are disregarded.<\/b><\/p>\n<p><b>Considering the floor plan provided, with all appliances in operation, the total power, in watts, will be:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_e7bb9268.png\" alt=\"\" width=\"774\" height=\"17\" name=\"Imagem 199\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>30-(PASUSP)<\/b><b>\u00a0A domestic refrigerator has a power of 180W. In a 24-hour period, the compressor works for about 10 hours, thus maintaining the appropriate temperature inside the appliance. Knowing that the operation of this refrigerator represents, on average, 25% of the total energy consumption, the monthly consumption, in kWh, of this residence can be estimated as:<\/b><\/p>\n<p><b>a) 54 b) 96 c) 128 d) 180 e) 216<\/b><\/p>\n<p><b>31-(ENEM-MEC)<\/b><b>\u00a0The efficiency of an energy conversion process is defined as the ratio between the production of useful energy or work and the total energy in the process. The figure shows a process in several stages. In this case, the overall efficiency will be equal to the product of the efficiencies of the individual stages. The energy input that is not transformed into useful work is lost in unusable forms (such as waste heat).<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_c4576a29.jpg\" alt=\"\" width=\"760\" height=\"232\" name=\"Imagem 41\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Increasing the efficiency of energy conversion processes involves saving resources and fuel. Which of the following proposals will result in the greatest increase in overall process efficiency?<\/b><\/p>\n<p><b>a) Increase the amount of fuel for burning in the power plant.<\/b><\/p>\n<p><b>b) Use incandescent lamps, which generate little heat and a lot of light.<\/b><\/p>\n<p><b>c) Keep the number of electrical appliances in homes to a minimum.<\/b><\/p>\n<p><b>d) Use cables with a smaller diameter in transmission lines in order to save conductive material.<\/b><\/p>\n<p><b>e) Use materials with better conductive properties in transmission lines and fluorescent lamps in homes.<\/b><\/p>\n<p><b>32-(UNESP-SP)<\/b><b>\u00a0The battery shown, with negligible resistance, was constructed using, as electrodes, a copper sheet immersed in an aqueous solution containing Cu\u00a0<\/b><sup><b>+2<\/b><\/sup><b>\u00a0ions (1mol.L\u00a0<\/b><sup><b>-1<\/b><\/sup><b>\u00a0) and a zinc sheet immersed in an aqueous solution containing Zn\u00a0<\/b><sup><b>+2<\/b><\/sup><b>\u00a0ions (1mol.L\u00a0<\/b><sup><b>-1<\/b><\/sup><b>\u00a0). In addition to the battery, whose potential difference is equal to 1.1 volts, the circuit consists of a small lamp and a switch Ch. With the switch closed, the copper electrode had an increase in mass of 63.5\u03bcg after 193s.\u00a0\u00a0\u00a0<\/b><b>\u00a0<\/b><b><\/b><b><\/b><b><\/b><b><\/b><b>\u00a0<\/b><b><\/b><b><\/b><b><\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_3b8abd19.jpg\" alt=\"\" width=\"768\" height=\"27\" name=\"Imagem 42\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_d2e76bd.jpg\" alt=\"\" width=\"467\" height=\"223\" name=\"Imagem 43\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Considering that the electric current remained constant during this time interval, the power dissipated by the lamp during this period was:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_fe6d89e2.png\" alt=\"\" width=\"774\" height=\"17\" name=\"Imagem 200\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>33-(UECE-CE)<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_81447c5b.jpg\" alt=\"\" width=\"197\" height=\"131\" name=\"Imagem 44\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_c73527f0.jpg\" alt=\"\" width=\"274\" height=\"133\" name=\"Imagem 45\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_e13551ae.jpg\" alt=\"\" width=\"283\" height=\"132\" name=\"Imagem 46\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>A 12 V battery with a 60 Ah charge capacity powers a sound system, providing it with<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_31798787.jpg\" alt=\"\" width=\"610\" height=\"187\" name=\"Imagem 47\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>system with a power of 60 W. Consider that the battery, at the beginning, is fully charged and will only power the sound system, so the battery voltage will remain at 12 V until the 60 Ah of charge is consumed. The maximum time of uninterrupted operation of the sound system in hours is:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_70a08cb7.png\" alt=\"\" width=\"774\" height=\"16\" name=\"Imagem 201\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>34-(PUC-MG)<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_7dc4520c.jpg\" alt=\"\" width=\"199\" height=\"93\" name=\"Imagem 48\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_2af10ca1.jpg\" alt=\"\" width=\"179\" height=\"94\" name=\"Imagem 49\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_13957d40.jpg\" alt=\"\" width=\"161\" height=\"98\" name=\"Imagem 50\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_35c4bc66.jpg\" alt=\"\" width=\"190\" height=\"95\" name=\"Imagem 51\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>When reading the nameplate of an electric shower, the following values \u200b\u200bare found: 127 V \u2013<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_2bb59c5.jpg\" alt=\"\" width=\"227\" height=\"135\" name=\"Imagem 52\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>4800W. It is CORRECT to state:<\/b><\/p>\n<p><b>a) This equipment consumes 4800J of energy every second of operation.<\/b><\/p>\n<p><b>b) The correct electrical current for this shower to operate is a maximum of 127 V.<\/b><\/p>\n<p><b>c) The voltage suitable for its operation cannot be higher than 4800 W.<\/b><\/p>\n<p><b>d) It is not possible to determine the correct value of the electric current with the available information.<\/b><\/p>\n<p><b>35-(UNESP-SP)<\/b><b>\u00a0\u00a0 A physics student built an electric heater using a resistor. When connected to a 110 V outlet, the heater was able to make 1 liter of\u00a0<a class=\"google-anno\" href=\"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica\/#\" data-google-vignette=\"false\" data-google-interstitial=\"false\">\u00a0<span class=\"google-anno-t\">water<\/span><\/a>\u00a0, initially at a temperature of 20 \u00b0C, reach its boiling point in 1 minute. Consider that 80% of the electrical energy was dissipated in the form of heat by the heater&#8217;s equivalent resistor, that the specific heat of water is 1 cal\/(g \u00b4 \u00b0C), that the density of water is 1 g\/cm3 and that 1 calorie is equal to 4 joules. Determine the value of the electrical resistance, in ohms, of the resistor used.<\/b><\/p>\n<p><b>36-(UFJF-MG)\u00a0<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_94dff6e.jpg\" alt=\"\" width=\"183\" height=\"99\" name=\"Imagem 53\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8d0cbf10.jpg\" alt=\"\" width=\"176\" height=\"99\" name=\"Imagem 54\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_f7aba66f.jpg\" alt=\"\" width=\"177\" height=\"101\" name=\"Imagem 55\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8586ea59.jpg\" alt=\"\" width=\"200\" height=\"103\" name=\"Imagem 56\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>The graph shows the electrical power, in kW, consumed in the residence of a resident of the city of Juiz de Fora,<\/b><\/p>\n<p><b>throughout the day. The residence is supplied with a voltage of 120 V. This residence has a<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_252e093c.jpg\" alt=\"\" width=\"365\" height=\"184\" name=\"Imagem 57\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>circuit breaker that trips if the electrical current exceeds a certain value, to prevent damage to the electrical installation. On the other hand, this circuit breaker is sized to support a current used in the operation of all appliances in the residence, which add up to a total power of 7.20 kW.<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_fa0084a4.jpg\" alt=\"\" width=\"341\" height=\"140\" name=\"Imagem 58\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>a) What is the maximum current value that the circuit breaker can withstand?<\/b><\/p>\n<p><b>b) What is the energy in kWh consumed throughout a day in this residence?<\/b><\/p>\n<p><b>c) What is the price to pay for a month of consumption, if 1kWh costs R$ 0.50?<\/b><\/p>\n<p><b>37-(UFLA-MG)\u00a0<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_da9c4f4a.jpg\" alt=\"\" width=\"240\" height=\"131\" name=\"Imagem 59\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_4ae3cace.jpg\" alt=\"\" width=\"212\" height=\"129\" name=\"graphics15\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_a14c624a.jpg\" alt=\"\" width=\"273\" height=\"131\" name=\"Imagem 61\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>The following figure represents the relationship between the electric potential difference volt (V) and the current intensity ampere (A) in an ohmic resistor. It is CORRECT to state that for a voltage of 150 V the resistor will dissipate a power of<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_462b0e95.jpg\" alt=\"\" width=\"372\" height=\"172\" name=\"Imagem 62\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>a) 960 W.\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) 1500 W.\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) 1200 W.\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) 9600 W.\u00a0<\/b><\/p>\n<p><b>38-(PUC-RJ)\u00a0<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8ad564a6.jpg\" alt=\"\" width=\"221\" height=\"126\" name=\"Imagem 63\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_72356fc0.jpg\" alt=\"\" width=\"146\" height=\"121\" name=\"Imagem 64\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_f8631f05.jpg\" alt=\"\" width=\"171\" height=\"125\" name=\"graphics16\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_74fff4d4.jpg\" alt=\"\" width=\"213\" height=\"123\" name=\"graphics17\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Three-temperature electric showers are widely used in Brazil. To install a shower, it is necessary to choose the power of the shower and the voltage that we will use in our electrical installation. In this way, if we install<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_91a473fb.jpg\" alt=\"\" width=\"260\" height=\"153\" name=\"Imagem 67\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>a 4,500 W shower using a voltage of 220 V, we can use a circuit breaker that can handle the passage of 21 A. If we want to connect another 4,500 W shower to a 110 V voltage network, which circuit breaker should we choose?<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_208f88b.png\" alt=\"\" width=\"774\" height=\"19\" name=\"Imagem 202\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>39-(UERJ-RJ)<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_545f844c.jpg\" alt=\"\" width=\"170\" height=\"102\" name=\"Imagem 68\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_a942ad02.jpg\" alt=\"\" width=\"155\" height=\"107\" name=\"Imagem 69\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_ae1b40d1.jpg\" alt=\"\" width=\"153\" height=\"107\" name=\"Imagem 70\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_af9e721a.jpg\" alt=\"\" width=\"272\" height=\"108\" name=\"Imagem 71\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>The table below shows the number of electrical devices in a home, the power consumed by each of them and the actual time of daily use in summer.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_fb82ad59.jpg\" alt=\"\" width=\"624\" height=\"84\" name=\"Imagem 72\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Consider the following values:<\/b><\/p>\n<p>\u2022\u00a0<b>absolute density of water: 1.0 g\/cm\u00a0<\/b><sup><b>3<\/b><\/sup><\/p>\n<p>\u2022\u00a0<b>specific heat of water: 1.0 cal.g\u00a0<\/b><sup><b>-1\u00a0<\/b><\/sup><sup><b>o<\/b><\/sup><b>\u00a0C\u00a0<\/b><sup><b>-1<\/b><\/sup><b>\u00a0<\/b><b><\/b><b><\/b><b><\/b><\/p>\n<p>\u2022\u00a0<b>1 cal = 4.2 J<\/b><\/p>\n<p>\u2022\u00a0<b>cost of 1 kWh = R$ 0.50<\/b><\/p>\n<p><b>During 30 days of summer, the total expenditure on these devices, in reais, is approximately:<\/b><\/p>\n<p><b>a) 234\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) 513\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) 666\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) 1026\u00a0<\/b><\/p>\n<p><b>40- (UERJ-RJ)<\/b><b>\u00a0The table below shows the number of electrical devices in a house, the power consumed by each of them and the actual time of daily use in the summer.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_49267ea7.jpg\" alt=\"\" width=\"709\" height=\"96\" name=\"Imagem 73\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Consider the following values:<\/b><\/p>\n<p>\u2022\u00a0<b>absolute density of water: 1.0 g\/cm\u00a0<\/b><sup><b>3<\/b><\/sup><\/p>\n<p>\u2022\u00a0<b>specific heat of water: 1.0 cal.g\u00a0<\/b><sup><b>-1\u00a0<\/b><\/sup><sup><b>o<\/b><\/sup><b>\u00a0C\u00a0<\/b><sup><b>-1<\/b><\/sup><b>\u00a0<\/b><b><\/b><b><\/b><b><\/b><\/p>\n<p>\u2022\u00a0<b>1 cal = 4.2 J<\/b><\/p>\n<p>\u2022\u00a0<b>cost of 1 kWh = R$ 0.50<\/b><\/p>\n<p><b>In winter, an electric heater is used every day to raise the temperature of 120 liters of\u00a0<a class=\"google-anno\" href=\"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-potencia-eletrica-energia-eletrica\/#\" data-google-vignette=\"false\" data-google-interstitial=\"false\">\u00a0<span class=\"google-anno-t\">water<\/span><\/a>\u00a0by 30 \u00baC.<\/b><\/p>\n<p><b>During 30 days of winter, the total cost of this device, in reais, is approximately:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_19024559.png\" alt=\"\" width=\"774\" height=\"15\" name=\"graphics18\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><span lang=\"en-US\"><b>41- (UNIRG-TO)<\/b><\/span><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_61f71b7f.jpg\" alt=\"\" width=\"298\" height=\"106\" name=\"Imagem 74\" align=\"BOTTOM\" border=\"0\" \/>\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_a9c5f671.jpg\" alt=\"\" width=\"236\" height=\"105\" name=\"Imagem 75\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>The figure below shows a stun gun used for self-defense.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_60a77369.jpg\" alt=\"\" width=\"490\" height=\"117\" name=\"Imagem 76\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>This device, when in operation, delivers a current of 2 mA (microamps) at a voltage of 50,000 volts, which is enough to incapacitate a person without causing permanent damage. The electrical power released during a shock with these characteristics, in watts, is<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_77b7c7.png\" alt=\"\" width=\"774\" height=\"18\" name=\"graphics19\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>42-(UFT-TO)<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_c7448e8c.jpg\" alt=\"\" width=\"233\" height=\"107\" name=\"Imagem 77\" align=\"BOTTOM\" border=\"0\" \/>\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_3b50a89a.jpg\" alt=\"\" width=\"245\" height=\"112\" name=\"Imagem 78\" align=\"BOTTOM\" border=\"0\" \/>\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_acd316bb.jpg\" alt=\"\" width=\"257\" height=\"112\" name=\"Imagem 79\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>A person takes 45 minutes to take a daily shower. It is known that his shower consumes 5000 Watts and a voltage of 220 Volts, and that the cost of energy is R$ 0.20 per [kW h]. How much does this person spend monthly on his showers?<\/b><\/p>\n<p><b>Consider that the person takes a shower a day, and that the month has 30 days.<\/b><\/p>\n<p><b>a) R$10.00\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) R$12.50\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) R$22.50\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) R$75.00\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>e) R$75.50<\/b><\/p>\n<p><b>43-(PUCS-RS)<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8b9c44b5.jpg\" alt=\"\" width=\"185\" height=\"87\" name=\"graphics20\" align=\"BOTTOM\" border=\"0\" \/>\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_6a70e224.jpg\" alt=\"\" width=\"208\" height=\"89\" name=\"Imagem 81\" align=\"BOTTOM\" border=\"0\" \/>\u00a0\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_2c3427b2.jpg\" alt=\"\" width=\"217\" height=\"94\" name=\"Imagem 82\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>An electrical device initially has an internal energy of 550 J. It then receives from an electric current an amount of energy per time equivalent to 50 W, and begins to release in the form of electromagnetic radiation an amount of energy per time equivalent to 20 W. When the electrical device reaches an internal energy of 1000 J, it melts. How long will it take for this to happen? (Neglect any other loss or gain of energy outside the processes mentioned above.)<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8543d21c.png\" alt=\"\" width=\"774\" height=\"19\" name=\"graphics21\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>44-(UESPI-PI)<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_85243f53.jpg\" alt=\"\" width=\"757\" height=\"81\" name=\"Imagem 83\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>A student pays R$40.00 (forty reais) per month to use a 5000 W electric shower.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_4d487ce4.jpg\" alt=\"\" width=\"181\" height=\"211\" name=\"Imagem 84\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>Knowing that this amount results from a fixed cost charge per kWh of electricity consumed monthly, he decides to save money by replacing this shower with another 4000 W one. If the new shower is used for the same amount of time as the old shower, the savings in one month will be:<\/b><\/p>\n<p><b>a) R$ 5.00\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) R$ 8.00\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) R$ 15.00\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) R$ 20.00\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>e) R$ 39.00\u00a0<\/b><\/p>\n<p><b>45-(ENEM-MEC)<\/b><b>\u00a0The electrical energy consumed in homes is measured in kilowatt-hours by means of a consumption meter. On this meter, from right to left, there are the unit, tens, hundreds and thousands pointers. If a pointer is between two numbers, the last number passed by the pointer is considered. Suppose that the measurements indicated in the following diagrams were made in a city where the price of a kilowatt-hour was R$ 0.20.<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_4a7adde4.jpg\" alt=\"\" width=\"604\" height=\"213\" name=\"Imagem 85\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>The amount to be paid for the registered electricity consumption would be<\/b><\/p>\n<p><b>a) R$ 41.80.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) R$ 42.00.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) R$ 43.00.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) R$ 43.80.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>e) R$ 44.00.<\/b><\/p>\n<p><b>46-(UNIFOR-CE)\u00a0<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_b4bbd23.jpg\" alt=\"\" width=\"170\" height=\"114\" name=\"Imagem 86\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_5dac3700.jpg\" alt=\"\" width=\"142\" height=\"115\" name=\"Imagem 87\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_eb204946.jpg\" alt=\"\" width=\"213\" height=\"117\" name=\"Imagem 88\" align=\"BOTTOM\" border=\"0\" \/>\u00a0<img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_3484b4c4.jpg\" alt=\"\" width=\"224\" height=\"118\" name=\"Imagem 89\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>Our energy matrix is \u200b\u200bpredominantly of hydraulic origin. Our plants, such as Itaip\u00fa, Sobradinho, Paulo Afonso and Tucuru\u00ed, are located at great distances from the centers<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_7b5b9d86.jpg\" alt=\"\" width=\"744\" height=\"118\" name=\"Imagem 90\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>energy consumers, making it necessary to transmit energy through extensive lines. The choice for this type of transmission, in high voltage and low intensity alternating current, occurs because:<\/b><\/p>\n<p><b>I. The transmission of large power at low voltage and low current is economically viable.<\/b><\/p>\n<p><b>II. High-intensity, low-voltage current transmission would require a large loss of power due to the heating of the transmission lines.<\/b><\/p>\n<p><b>III. Alternating current transmission allows for simplified voltage reduction through transformers at step-down stations in consumer centers.<\/b><\/p>\n<p><b>a) I, only.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) II, only.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) III, only.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) I and III, only.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>e) II and III, only.<\/b><\/p>\n<p><b>47- (UERJ-RJ)<\/b><b>\u00a0To start a truck, its 12 V battery must establish<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_7ec5863.jpg\" alt=\"\" width=\"261\" height=\"142\" name=\"Imagem 91\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p>\u00a0<b>a current of 100 A for one minute. The energy, in joules, supplied by the battery corresponds to:<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_6dad1ca5.png\" alt=\"\" width=\"775\" height=\"16\" name=\"graphics22\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>48-(ENEM-MEC)<\/b><b>\u00a0Observe the following table. It contains technical specifications contained in the instruction manual provided by<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8838a11b.jpg\" alt=\"\" width=\"743\" height=\"229\" name=\"Imagem 92\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>by the manufacturer of an electric tap. Considering that the highest power model of the 220 V version of the Supreme tap was inadvertently connected to a network with a nominal voltage of 127 V, and that the appliance is configured to work at its<\/b><\/p>\n<p><b>maximum power. What is the approximate power value when turning on the tap?<\/b><\/p>\n<p><b>a) 1,830 W\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>b) 2,800 W\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>c) 3,200 W\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>d) 4,030 W\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/p>\n<p><b>e) 5,500 W<\/b><\/p>\n<p><b>49-(UFPA-PA)<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_8655a113.jpg\" alt=\"\" width=\"444\" height=\"128\" name=\"Imagem 93\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>A solar panel with an area of \u200b\u200b1 m2\u00a0<\/b><sup><b>produces<\/b><\/sup><b>\u00a0about 0.5 kW.h per day.\u00a0<\/b><b>With this in mind, a consumer interested in this energy source decided to evaluate his daily consumption needs, which are listed in the table below.<\/b><b>\u00a0<\/b><b><\/b><b>\u00a0<\/b><sup><b>\u00a0<\/b><\/sup><b><\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_b014a330.jpg\" alt=\"\" width=\"623\" height=\"152\" name=\"Imagem 94\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>From this data, the minimum number of solar panels that this consumer needs to purchase to meet their needs<\/b><\/p>\n<p><b>of daily energy consumption is<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_2317aa8a.png\" alt=\"\" width=\"774\" height=\"17\" name=\"graphics23\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>50-(ENEM-MEC)\u00a0\u00a0<\/b><\/p>\n<p><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_392ea019.jpg\" alt=\"\" width=\"191\" height=\"119\" name=\"Imagem 95\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>First generation biofuels are derived from soybeans, corn and sugar cane and are produced through<\/b><\/p>\n<p align=\"CENTER\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/fisicaevestibular.com.br\/novo\/wp-content\/uploads\/migracao\/eletrcidade\/portencia\/i_836871f4d8e4db1a_html_b0e6076d.jpg\" alt=\"\" width=\"703\" height=\"161\" name=\"Imagem 96\" align=\"BOTTOM\" border=\"0\" \/><\/p>\n<p><b>fermentation. Biofuels derived from cellulosic material or second-generation biofuels \u2013 colloquially called \u201cgrass gasoline\u201d \u2013 are those produced from wood waste (sawdust, for example), corn stalks, wheat straw or fast-growing grass and are an alternative to the problems faced by first-generation fuels, since the raw materials are cheap and abundant.<\/b><\/p>\n<p><b>DALE, BE; HUBER, GW Gasoline from grass and other plants.\u00a0<\/b><span lang=\"en-US\"><b>Scientific American Brazil. Aug. 2009. n.\u00b0 87<\/b><\/span><b>\u00a0<\/b><b><\/b><\/p>\n<p><b>(adapted).<\/b><\/p>\n<p><b>The text shows one of the points of view regarding the use of biofuels today, which:<\/b><\/p>\n<p><b>a) they are energy matrices with a lower pollution load for the environment and can provide the generation of new jobs, however, to be offered at a low cost, the technology for degrading cellulose in second-generation biofuels must be extremely efficient.<\/b><\/p>\n<p><b>b) they offer multiple difficulties, as production is expensive, their implementation does not generate jobs, and care must be taken with environmental risks, as they offer the same risks as the use of fossil fuels.<\/b><\/p>\n<p><b>c) being second generation, they are produced using a technology that causes social problems, mainly due to the fact that the raw material is abundant and easily found, which prevents the generation of new jobs.<\/b><\/p>\n<p><b>d) being first and second generation, they are produced by technologies that must undergo a careful evaluation regarding their use, as one faces the problem of lack of space for planting the raw material and the other prevents the generation of new sources of employment.<\/b><\/p>\n<p><b>e) can lead to serious economic and social problems, as replacing the use of oil negatively affects the entire production chain as it excludes several sources of employment in refineries, gas stations and in the transportation of oil and gasoline.<\/b><\/p>\n<h3><a title=\"Commented resolution of entrance exam exercises on Electrical power \u2013 Electrical energy\" href=\"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/potencia-eletrica-energia-eletrica\/resolucao-comentada-dos-exercicios-de-vestibulares-sobre-potencia-eletrica-energia-eletrica\/\">Check the answer key and commented solutions for the exercises\u00a0<\/a><\/h3>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>ELECTRIC ENERGY \u2013 RESOLUTION Entrance exam exercises with commented solutions on Electrical power \u2013 Electrical energy 01-(UNICAMP-SP)\u00a0Consider the following equipment operating at maximum power during &nbsp; &nbsp; one hour: a 100W light bulb, a\u00a0Beetle\u00a0\u00a0engine , a truck engine, a 40W light bulb, an iron. &nbsp; &nbsp; a) Which lamp consumes less energy? &nbsp; &nbsp; b) Which equipment consumes the most<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1711,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"class_list":["post-1713","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1713","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/comments?post=1713"}],"version-history":[{"count":6,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1713\/revisions"}],"predecessor-version":[{"id":12227,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1713\/revisions\/12227"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1711"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=1713"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}