{"id":1812,"date":"2016-01-25T00:22:58","date_gmt":"2016-01-25T00:22:58","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=1812"},"modified":"2024-12-27T20:09:05","modified_gmt":"2024-12-27T20:09:05","slug":"calculo-de-correntes-eletricas-tensoes-e-potencias-eletricas-em-circuitos-mistos","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/calculo-de-correntes-eletricas-tensoes-e-potencias-eletricas-em-circuitos-mistos\/","title":{"rendered":"C\u00e1lculo de correntes el\u00e9tricas, tens\u00f5es e pot\u00eancias el\u00e9tricas em circuitos mistos"},"content":{"rendered":"

C\u00e1lculo de correntes el\u00e9tricas, tens\u00f5es e pot\u00eancias el\u00e9tricas em circuitos mistos<\/b><\/span><\/span><\/span><\/p>\n

\u00a0<\/span><\/p>\n

A <\/b><\/span><\/span><\/span>resolu\u00e7\u00e3o desse tipo de associa\u00e7\u00f5es<\/b><\/span><\/span><\/span> \u00e9 feita por <\/b><\/span><\/span><\/span>etapas at\u00e9 chegar ao resistor equivalente<\/b><\/span><\/span><\/span> e depois <\/b><\/span><\/span><\/span>ir retornando e achando o que \u00e9 pedido como voc\u00ea pode observar nos exemplos a seguir que devem ser analisados com muita aten\u00e7\u00e3o.<\/b><\/span><\/span><\/span><\/p>\n

a)<\/b><\/span><\/span><\/span> Determine a <\/b><\/span><\/span><\/span>intensidade da corrente em cada ramo<\/b><\/span><\/span><\/span>; a <\/b><\/span><\/span><\/span>tens\u00e3o entre A e C<\/b><\/span><\/span><\/span> e a <\/b><\/span><\/span><\/span>pot\u00eancia el\u00e9trica dissipada pelo resistor de 9\u2126, considerando U<\/b><\/span><\/span><\/span>AB <\/b><\/span><\/span><\/sub><\/span>= 24V<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Inicialmente voc\u00ea deve <\/b><\/span><\/span><\/span>calcular a resist\u00eancia equivalente R<\/b><\/span><\/span><\/span>eq<\/b><\/span><\/span><\/sub><\/span> conforme seq\u00fc\u00eancia a seguir<\/b><\/span><\/span><\/span>:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Achar agora a <\/b><\/span><\/span><\/span>corrente el\u00e9trica<\/b><\/span><\/span><\/span> <\/b>total i<\/b><\/span><\/span><\/span> e ir retornando colocando-a em cada etapa (III, II e I) e colocando tamb\u00e9m todas as correntes em cada ramo do circuito, nomeando-as:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Colocando na seq\u00fc\u00eancia I, II e III:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A seguir, <\/b><\/span><\/span><\/span>em II<\/b><\/span><\/span><\/span>, vamos <\/b><\/span><\/span><\/span>calcular a ddp (tens\u00e3o) U<\/b><\/span><\/span><\/span> nos <\/b><\/span><\/span><\/span>trechos AC e CB<\/b><\/span><\/span><\/span> lembrando que como est\u00e3o em <\/b><\/span><\/span><\/span>s\u00e9rie a corrente i = 3 A \u00e9 a mesma nos dois resistores:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Agora, <\/b><\/span><\/span><\/span>em I<\/b><\/span><\/span><\/span>, na associa\u00e7\u00e3o <\/b><\/span><\/span><\/span>paralelo do trecho CB<\/b><\/span><\/span><\/span>, onde <\/b><\/span><\/span><\/span>U<\/b><\/span><\/span><\/span>CB<\/b><\/span><\/span><\/sub><\/span> = 18 V<\/b><\/span><\/span><\/span>, que \u00e9 o <\/b><\/span><\/span><\/span>mesmo para os dois<\/b><\/span><\/span><\/span> <\/b>resistores<\/b><\/span><\/span><\/span>, vamos <\/b><\/span><\/span><\/span>calcular i\u2019 e i\u2019\u2019<\/b><\/span><\/span><\/span>:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Pot\u00eancia el\u00e9trica<\/b><\/span><\/span><\/span> <\/b>dissipada no resistor de 9 \u2126<\/b><\/span><\/span><\/span>, percorrido por <\/b><\/span><\/span><\/span>i\u2019\u2019 = 2 A<\/b><\/span><\/span><\/span> \"\" <\/b><\/span><\/span><\/span>P<\/b><\/span><\/span><\/span>9\u2126<\/b><\/span><\/span><\/sub><\/span> = R.i\u2019\u2019<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span> = 9.2<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span> \"\"<\/b><\/span><\/span><\/span><\/p>\n

P<\/b><\/span><\/span><\/span>9\u2126<\/b><\/span><\/span><\/sub><\/span> = 36<\/b><\/span><\/span><\/span> <\/b>W.<\/b><\/span><\/span><\/span><\/p>\n

Respostas: <\/b><\/span><\/span><\/span>i = 3 A; i\u2019 = 1 A e i\u2019\u2019 = 2 A; U<\/b><\/span><\/span><\/span>AC<\/b><\/span><\/span><\/sub><\/span> = 6 V e P<\/b><\/span><\/span><\/span>9\u2126<\/b><\/span><\/span><\/sub><\/span> = 36 W<\/b><\/span><\/span><\/span><\/p>\n

b)<\/b><\/span><\/span><\/span> Calcule a <\/b><\/span><\/span><\/span>intensidade de corrente el\u00e9trica em cada ramo do circuito abaixo<\/b><\/span><\/span><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Resolu\u00e7\u00e3o: Calculando a resist\u00eancia equivalente e a corrente el\u00e9trica total i:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

\u00a0<\/span><\/p>\n

c)<\/b><\/span><\/span><\/span> No <\/b><\/span><\/span><\/span>circuito<\/b><\/span><\/span><\/span> representado no <\/b><\/span><\/span><\/span>esquema abaixo<\/b><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span>todos<\/b><\/span><\/span><\/span> os resistores tem <\/b><\/span><\/span><\/span>resist\u00eancia igual a 10\u2126.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Sendo a <\/b><\/span><\/span><\/span>corrente el\u00e9trica em R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span> <\/b>de <\/b><\/span><\/span><\/span>i<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span> = 2,0 A<\/b><\/span><\/span><\/span>, <\/b><\/span><\/span><\/span>calcule<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>corrente el\u00e9trica nos outros resistores, a diferen\u00e7a de potencial em<\/b><\/span><\/span><\/span> <\/b>cada resistor e a<\/b><\/span><\/span><\/span> <\/b>diferen\u00e7a de potencial do gerador.<\/b><\/span><\/span><\/span><\/p>\n

Resolu\u00e7\u00e3o: Colocando<\/b><\/span><\/span><\/span> as <\/b><\/span><\/span><\/span>correntes<\/b><\/span><\/span><\/span> sabendo que no <\/b><\/span><\/span><\/span>gerador a corrente total i sai do p\u00f3lo positivo<\/b><\/span><\/span><\/span>:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

Finalmente <\/b><\/span><\/span><\/span>observe <\/b><\/span><\/span><\/span>na figura que <\/b><\/span><\/span><\/span>i = i<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span> + i<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sub><\/span> = 6 + 4 <\/b><\/span><\/span><\/span>i = 10 A<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

d)<\/b><\/span><\/span><\/span> Na <\/b><\/span><\/span><\/span>associa\u00e7\u00e3o abaixo<\/b><\/span><\/span><\/span> a <\/b><\/span><\/span><\/span>tens\u00e3o entre os pontos P e Q vale U<\/b><\/span><\/span><\/span>PQ <\/b><\/span><\/span><\/sub><\/span>= 4R<\/b><\/span><\/span><\/span> e o <\/b><\/span><\/span><\/span>potencial no ponto P \u00e9 maior que o potencial no ponto Q.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Determine a <\/b><\/span><\/span><\/span>intensidade, o sentido da corrente el\u00e9trica e a pot\u00eancia el\u00e9trica dissipada em cada um dos resistores.<\/b><\/span><\/span><\/span><\/p>\n

O <\/b><\/span><\/span><\/span>sentido da corrente el\u00e9trica<\/b><\/span><\/span><\/span> \u00e9 de <\/b><\/span><\/span><\/span>P para Q<\/b><\/span><\/span><\/span> (do maior para o menor potencial)<\/b><\/span><\/span><\/span><\/p>\n

Observe que <\/b><\/span><\/span><\/span>existe curto circuito<\/b><\/span><\/span><\/span>\u00a0\"\"\u00a0 marcando os <\/b><\/span><\/span><\/span>n\u00f3s e colocando letras nos mesmos<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Refazendo o circuito <\/b><\/span><\/span><\/span>e<\/b><\/span><\/span><\/span> calculando a resist\u00eancia equivalente:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Calculando a <\/b><\/span><\/span><\/span>intensidade da corrente el\u00e9trica total i<\/b><\/span><\/span><\/span> sendo fornecida a <\/b><\/span><\/span><\/span>tens\u00e3o (ddp) entre P e Q, U<\/b><\/span><\/span><\/span>PQ<\/b><\/span><\/span><\/sub><\/span> = 4R:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Voltando ao <\/b><\/span><\/span><\/span>circuito original<\/b><\/span><\/span><\/span>:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

C\u00e1lculo da <\/b><\/span><\/span><\/span>pot\u00eancia el\u00e9trica dissipada<\/b><\/span><\/span><\/span> em <\/b><\/span><\/span><\/span>cada resistor:<\/b><\/span><\/span><\/span><\/p>\n

P = R.i<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span> <\/b>= R.(4)<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>\u00a0 \"\"\u00a0\u00a0<\/b><\/span><\/span><\/span>P =16 R.<\/b><\/span><\/span><\/span><\/p>\n

Respostas:<\/b><\/span><\/span><\/span> <\/b>Corrente el\u00e9trica total<\/b><\/span><\/span><\/span>\u00a012A<\/b><\/span><\/span><\/span>\u00a0 \"\"\u00a0 <\/b><\/span><\/span><\/span>corrente el\u00e9trica em cada resistor\u00a0<\/b><\/span><\/span><\/span>4 A<\/b><\/span><\/span><\/span>\u00a0\"\"<\/b><\/span><\/span><\/span>\u00a0 <\/b><\/span><\/span><\/span>sentido<\/b><\/span><\/span><\/span> de <\/b><\/span><\/span><\/span>cada corrente<\/b><\/span><\/span><\/span> \"\"\u00a0<\/b><\/span><\/span><\/span>de P para Q<\/b><\/span><\/span><\/span>\u00a0<\/b><\/span><\/span><\/span>\u00a0\"\" <\/b><\/span><\/span><\/span>pot\u00eancia el\u00e9trica<\/b><\/span><\/span><\/span> dissipada por<\/b><\/span><\/span><\/span>cada resistor \"\" \u00a0<\/b><\/span><\/span><\/span>P = 16R.<\/b><\/span><\/span><\/span><\/p>\n

O que voc\u00ea deve saber, informa\u00e7\u00f5es e dicas<\/b><\/span><\/span><\/span><\/p>\n

\"\" Saber as caracter\u00edsticas das associa\u00e7\u00f5es s\u00e9rie e paralelo, fornecidas a seguir:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"\"\" Sabendo as caracter\u00edsticas dessas duas associa\u00e7\u00f5es (s\u00e9rie e paralelo),<\/b><\/span><\/span><\/span> para que voc\u00ea possa <\/b><\/span><\/span><\/span>dominar a resolu\u00e7\u00e3o de exerc\u00edcios sobre associa\u00e7\u00f5es mistas, voc\u00ea deve treinar <\/b><\/span><\/span><\/span>fazendo muitos exerc\u00edcios.<\/b><\/span><\/span><\/span><\/p>\n

Selecionei <\/b><\/span><\/span><\/span>alguns que podem ajud\u00e1-lo: 06, 09, 11, 13, 17, 18, 22, 37 e 41.<\/b><\/span><\/span><\/span><\/p>\n

\nConfira os exerc\u00edcios selecionados!<\/span><\/a><\/h3>\n","protected":false},"excerpt":{"rendered":"

C\u00e1lculo de correntes el\u00e9tricas, tens\u00f5es e pot\u00eancias el\u00e9tricas em circuitos mistos \u00a0 A resolu\u00e7\u00e3o desse tipo de associa\u00e7\u00f5es \u00e9 feita por etapas at\u00e9 chegar ao resistor equivalente e depois ir retornando e achando o que \u00e9 pedido como voc\u00ea pode observar nos exemplos a seguir que devem ser analisados com muita aten\u00e7\u00e3o. a) Determine a intensidade da corrente em cada<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1676,"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-1812","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1812","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=1812"}],"version-history":[{"count":7,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1812\/revisions"}],"predecessor-version":[{"id":12242,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1812\/revisions\/12242"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1676"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=1812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}