{"id":1864,"date":"2016-01-25T01:11:23","date_gmt":"2016-01-25T01:11:23","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=1864"},"modified":"2024-08-19T14:10:47","modified_gmt":"2024-08-19T14:10:47","slug":"exercicios-de-vestibulares-com-resolucao-comentada-sobre-circuitos-compostos","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/eletricidade\/eletrodinamica\/circuitos-compostos\/exercicios-de-vestibulares-com-resolucao-comentada-sobre-circuitos-compostos\/","title":{"rendered":"Circuitos Compostos – Resolu\u00e7\u00e3o"},"content":{"rendered":"

Exerc\u00edcios de vestibulares com resolu\u00e7\u00e3o comentada sobre<\/b><\/span><\/span><\/span><\/p>\n

Circuitos Compostos<\/b><\/span><\/span><\/span><\/p>\n

<\/a><\/p>\n

01-(UFU-MG)<\/b><\/span><\/span><\/span> Considera o trecho de um circuito el\u00e9trico apresentado a seguir, contendo um resistor R, um gerador de for\u00e7a eletromotriz E e um fio ideal AB. Os pontos A, C e D n\u00e3o se ligam diretamente no circuito.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\u00c9 correto afirmar que<\/b><\/span><\/span><\/span><\/p>\n

a) a pot\u00eancia dissipada no resistor R depende, diretamente, da intensidade da corrente que o atravessa e, inversamente, da diferen\u00e7a de potencial entre B e D.<\/b><\/span><\/span><\/span><\/p>\n

b) a aplica\u00e7\u00e3o da 1<\/b><\/span><\/span><\/span>a<\/b><\/span><\/span><\/sup><\/span>\u00a0Lei de Kirchhoff (lei dos n\u00f3s) no ponto B garante a conserva\u00e7\u00e3o da carga el\u00e9trica no trecho apresentado.<\/b><\/span><\/span><\/span><\/p>\n

c) independentemente do restante do circuito, h\u00e1 conserva\u00e7\u00e3o de energia no trecho apresentado, o que imp\u00f5e que Ei = R[i(r)]<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sup><\/span>, sendo i a intensidade da corrente atrav\u00e9s do gerador e i(r) a intensidade da corrente que percorre o resistor.<\/b><\/span><\/span><\/span><\/p>\n

d) a diferen\u00e7a de potencial entre os pontos C e A (V<\/b><\/span><\/span><\/span>C<\/b><\/span><\/span><\/sub><\/span>\u00a0\u2013 V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>) \u00e9 zero.<\/b><\/span><\/span><\/span><\/p>\n

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

02-(PUC-SP)<\/b><\/span><\/span><\/span> <\/b>Entre os pontos A e B \u00e9 mantida uma tens\u00e3o U=20V. A corrente que atravessa esse trecho tem intensidade<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

03-(UNESP-SP)<\/b><\/span><\/span><\/span> <\/b>Tr\u00eas resistores, P, Q e S, cujas resist\u00eancias valem 10\u2126, 20\u2126 e 20\u2126 respectivamente, est\u00e3o ligados ao ponto A de um circuito. As correntes que passam por P e por Q s\u00e3o 1,00 A e 0,50 A, como mostra a figura.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

a) Qual \u00e9 a ddp entre A e C?<\/b><\/span><\/span><\/span><\/p>\n

b) Qual \u00e9 a ddp entre B e C?<\/b><\/span><\/span><\/span><\/p>\n

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

04-(PUC-SP)<\/b><\/span><\/span><\/span> <\/b>No circuito da figura, a diferen\u00e7a de potencial V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\u00a0\u2013 V<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>, com a chave K aberta, tem valor:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

05-(PUC-SP)<\/b><\/span><\/span><\/span> <\/b>Com rela\u00e7\u00e3o ao circuito do exerc\u00edcio anterior: Fechando a chave K da figura anterior, a diferen\u00e7a de potencial V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\u00a0\u2013 V<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>\u00a0passa a ter valor:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

06-(UNESP-SP)<\/b><\/span><\/span><\/span> <\/b>O esquema representa duas pilhas ligadas em paralelo, com as resist\u00eancias internas indicadas.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

a) Qual o valor da corrente que circula pelas pilhas?<\/b><\/span><\/span><\/span><\/p>\n

b) Qual \u00e9 o valor da diferen\u00e7a de potencial entre os pontos A e B e qual \u00e9 o ponto de maior potencial?<\/b><\/span><\/span><\/span><\/p>\n

c) Qual das duas pilhas est\u00e1 funcionando como receptor?<\/b><\/span><\/span><\/span><\/p>\n

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

07-(UFPE-PE)<\/b><\/span><\/span><\/span> <\/b>Calcule o potencial el\u00e9trico no ponto A, em volts, considerando que as baterias t\u00eam<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

resist\u00eancias internas desprez\u00edveis e que o potencial no ponto B \u00e9 igual a 15 volts.<\/b><\/span><\/span><\/span><\/p>\n

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

08-(UFPEL-RS)<\/b><\/span><\/span><\/span> <\/b>Num circuito de corrente cont\u00ednua, ao percorrermos uma malha fechada, partindo de um determinado ponto, observamos que as varia\u00e7\u00f5es de potencial el\u00e9trico sofridas pelos portadores de carga \u00e9 tal que, ao retornarmos ao ponto de partida, obtemos o mesmo valor para o potencial el\u00e9trico.<\/b><\/span><\/span><\/span><\/p>\n

Baseado no texto e em seus conhecimentos, o fato descrito acima \u00e9 uma consequ\u00eancia do princ\u00edpio da conserva\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/p>\n

a) da carga.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

b) da energia.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

c) da massa.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

d) da quantidade de movimento.\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

e) da pot\u00eancia el\u00e9trica.<\/b><\/span><\/span><\/span><\/p>\n

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

09- (MACKENZIE-SP)<\/b><\/span><\/span><\/span> <\/b>Duas baterias tem a mesma for\u00e7a eletromotriz (E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>)\u00a0 e resist\u00eancias internas respectivamente iguais a r<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0e r<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>. Elas s\u00e3o ligadas em s\u00e9rie a um resistor externo de resist\u00eancia R.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

O valor de R que tornar\u00e1 nula a diferen\u00e7a de potencial entre os terminais da primeira bateria ser\u00e1 igual a:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

10- (UFPA)<\/b><\/span><\/span><\/span> <\/b>No circuito a seguir, i = 2A, R = 2\u2126, E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= 10V, r<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= 0,5\u2126, E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 3,0V e r<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 1,0\u2126. Sabendo que o potencial no ponto A \u00e9 de 4V, podemos afirmar que os potenciais, em volts, nos pontos B, C e D s\u00e3o, respectivamente:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

11-(UFSC-SC) No circuito da figura, determine a intensidade da corrente i<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>, que ser\u00e1 lida no amper\u00edmetro A, supondo-o ideal (isto \u00e9, com resist\u00eancia interna nula).<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Dados: E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=100V, E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=52V, R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=4\u2126, R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=10\u2126, R<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>=2\u2126, i<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=10A.<\/b><\/span><\/span><\/span><\/p>\n

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

12-(UFPB-PB)<\/b><\/span><\/span><\/span> <\/b>Tendo-se no circuito abaixo, R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=2\u2126, R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=4\u2126 e R<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>=6\u2126, i<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=2 A e i<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>=1 A, determine:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

a) a corrente i<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0que percorre o resistor R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>;<\/b><\/span><\/span><\/span><\/p>\n

b) a for\u00e7a eletromotriz E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

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

\u00a0<\/span>(UFPA)<\/b><\/span><\/span><\/span> <\/b>A figura representa um circuito el\u00e9trico e refere-se \u00e0s quest\u00f5es de n\u00fameros <\/b><\/span><\/span><\/span>13, 14 e 15:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Dados: R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= 109\/11\u2126, R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 2\u2126,\u00a0 R<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>\u00a0= 4\u2126,\u00a0 R<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sub><\/span>\u00a0= 6\u2126, E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= 4V, r<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= 0,5\u2126, \u00a0E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 2V e r<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 0,5\u2126<\/b><\/span><\/span><\/span><\/p>\n

13-(UFPA)<\/b><\/span><\/span><\/span> <\/b>A corrente el\u00e9trica que passa pelo resistor R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0vale, em amp\u00e8res:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

14-(UFPA)<\/b><\/span><\/span><\/span> <\/b>A diferen\u00e7a de potencial entre os terminais do resistor R<\/b><\/span><\/span><\/span>4<\/b><\/span><\/span><\/sub><\/span>, em volts, vale:<\/b><\/span><\/span><\/span><\/p>\n

a) 2.\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><\/span><\/span><\/span><\/p>\n

b) 1.\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><\/span><\/span><\/span><\/p>\n

c) 1\/6.\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><\/span><\/span><\/span><\/p>\n

d) 2\/9.\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><\/span><\/span><\/span><\/p>\n

e) 2\/11.<\/b><\/span><\/span><\/span><\/p>\n

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

15-(UFPA) <\/b><\/span><\/span><\/span>A pot\u00eancia dissipada pelo resistor R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>, em watts, vale:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

16- (UFC-CE)<\/b><\/span><\/span><\/span> <\/b>Considere o circuito da figura a seguir.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

a) Utilize as leis de Kirchhoff para encontrar as correntes I<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>, I<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0e I<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span><\/p>\n

b) Encontre a diferen\u00e7a de potencial V<\/b><\/span><\/span><\/span>A<\/b><\/span><\/span><\/sub><\/span>\u00a0\u2013 V<\/b><\/span><\/span><\/span>B<\/b><\/span><\/span><\/sub><\/span>\u00a0.<\/b><\/span><\/span><\/span><\/p>\n

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

17-(UFMG-MG)<\/b><\/span><\/span><\/span> <\/b>No circuito esquematizado a seguir, o amper\u00edmetro ideal indica uma corrente de intensidade 2,0A. O valor da resist\u00eancia R da l\u00e2mpada, em ohms, \u00e9 igual a:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

18-(UEL-PR)<\/b><\/span><\/span><\/span>\u00a0 <\/b><\/span><\/span><\/span>Dados cinco resistores \u00f4hmicos, sendo quatro resistores R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= 3 \u03a9 e um resistor R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 6 \u03a9 e tr\u00eas baterias ideais, sendo E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>= 6,0V e E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=E<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>=12,0V.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Considerando que esses elementos fossem arranjados conforme o circuito da figura, assinale a alternativa que indica o valor correto para a diferen\u00e7a de potencial entre os pontos a e b [Uab ou ( Va \u2013 Vb )]:<\/b><\/span><\/span><\/span><\/p>\n

a) \u2013 3,0V\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0 \u00a0<\/b><\/span><\/span><\/span><\/p>\n

b) 3,0V \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

c) 10 ,0 V \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

d) 6,0V \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

e) \u2013 10,0V<\/b><\/span><\/span><\/span><\/p>\n

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

19-(UFLA-MG)<\/b><\/span><\/span><\/span> <\/b>No circuito apresentado na figura a seguir, est\u00e3o representadas diversas fontes de for\u00e7a eletromotriz de resist\u00eancia<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

interna desprez\u00edvel que alimentam os resistores R =1,75\u2126 e R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=1,25\u2126. A corrente i no circuito \u00e9 de:<\/b><\/span><\/span><\/span><\/p>\n

a) 6,0 A\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><\/span><\/span><\/span><\/p>\n

b) 5,0 A\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><\/span><\/span><\/span><\/p>\n

c) 4,5 A\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><\/span><\/span><\/span><\/p>\n

d) 2,0 A\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><\/span><\/span><\/span><\/p>\n

e) 3,0 A<\/b><\/span><\/span><\/span><\/p>\n

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

20-(ULFA)<\/b><\/span><\/span><\/span> <\/b>O circuito mostrado abaixo pode ser alimentado por dois geradores G<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0e G<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0com forca eletromotriz E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=48V e resist\u00eancia el\u00e9trica interna desprez\u00edvel.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\u00a0O gerador G<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0pode ser acoplado ao circuito por uma chave CH, que inicialmente esta aberta. Resolva os itens a seguir:<\/b><\/span><\/span><\/span><\/p>\n

a) Considerando a chave CH aberta, calcule a corrente el\u00e9trica fornecida pelo gerador G<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

b) Considerando, ainda, a chave CH aberta, calcule a DDP entre os pontos D e B.<\/b><\/span><\/span><\/span><\/p>\n

c) Considerando, agora, a chave CH fechada, calcule a corrente que passa no resistor entre os pontos D e C.<\/b><\/span><\/span><\/span><\/p>\n

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

21-(UEM-PR)<\/b><\/span><\/span><\/span> <\/b>Relativamente ao circuito el\u00e9trico representado na figura a seguir, assuma que R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>=10,0 \u2126, R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=15,0\u2126, R<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>=5,0 \u2126, E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>= 240,0 mV e E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>=100,0 mV. Assinale o que for correto.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

01) No n\u00f3 b, i<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= i<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0\u2013 i<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

02) A corrente el\u00e9trica i<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0que atravessa o resistor R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00e9 menor do que a corrente i<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>\u00a0que atravessa o resistor R<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

04) O valor da pot\u00eancia el\u00e9trica fornecida ao circuito pelo dispositivo de for\u00e7a-eletromotriz E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00e9 2,88 mW.<\/b><\/span><\/span><\/span><\/p>\n

08) Aplicando a Lei das Malhas (de Kirchhoff) \u00e0 malha externa ‘abcda’ do circuito, obt\u00e9m-se a equa\u00e7\u00e3o E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0+ E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>i<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0+ R<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>i<\/b><\/span><\/span><\/span>3<\/b><\/span><\/span><\/sub><\/span>.<\/b><\/span><\/span><\/span><\/p>\n

16) A diferen\u00e7a de potencial el\u00e9trico Vb – Vd entre os pontos b e d do circuito vale 150,0 mV.<\/b><\/span><\/span><\/span><\/p>\n

32) A pot\u00eancia dissipada no resistor R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0vale 1,50 mW.<\/b><\/span><\/span><\/span><\/p>\n

64) O valor da pot\u00eancia el\u00e9trica dissipada pelo dispositivo de for\u00e7a-contra-eletromotriz E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00e9 0,40 mW.<\/b><\/span><\/span><\/span><\/p>\n

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

22-(ITA-SP)<\/b><\/span><\/span><\/span> <\/b>No circuito da figura t\u00eam-se as resist\u00eancias R, R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0e R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>, e as fontes V<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0e V<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>, aterradas. A corrente i \u00e9:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

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

23-(ITA-SP)<\/b><\/span><\/span><\/span> <\/b>Um t\u00e9cnico em eletr\u00f4nica deseja medir a corrente que passa pelo resistor de 12\u2126 no circuito da figura. Para tanto, ele disp\u00f5e apenas de um galvan\u00f4metro e uma caixa de resistores. O galvan\u00f4metro possui resist\u00eancia interna R<\/b><\/span><\/span><\/span>G<\/b><\/span><\/span><\/sub><\/span>=5k\u2126 e suporta, no m\u00e1ximo, uma corrente de 0,1mA.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Determine o valor m\u00e1ximo do resistor R a ser colocado em paralelo com o galvan\u00f4metro para que o t\u00e9cnico consiga medir a corrente.<\/b><\/span><\/span><\/span><\/p>\n

24- (UEM-PR)\u00a0<\/b><\/span><\/span><\/span><\/p>\n

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

\u00a0Analise o circuito el\u00e9trico representado na figura abaixo e assinale o que for correto.<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

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

01. A corrente i \u00e9 3 A.<\/b><\/span><\/span><\/span><\/p>\n

02. A resist\u00eancia interna r \u00e9 5 \u03a9.<\/b><\/span><\/span><\/span><\/p>\n

04. A for\u00e7a eletromotriz e \u00e9 16 V.<\/b><\/span><\/span><\/span><\/p>\n

08. A diferen\u00e7a de potencial entre os pontos a e b \u00e9 10 V.<\/b><\/span><\/span><\/span><\/p>\n

16. O circuito el\u00e9trico englobado pelo ret\u00e2ngulo central em destaque, na figura acima, pode representar uma bateria sendo carregada.<\/b><\/span><\/span><\/span><\/p>\n

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

25-(UPE-PE)<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Um circuito com duas malhas cont\u00e9m duas fontes de tens\u00e3o constante E<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= E<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 14 V e tr\u00eas resistores R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0= 1,0 ohm, R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0= 3,0 ohms e R = 1,0 ohm, conforme mostrado na figura a seguir:<\/b><\/span><\/span><\/span><\/p>\n

Analise as seguintes proposi\u00e7\u00f5es:<\/b><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

I. A corrente que passa pelo resistor R<\/b><\/span><\/span><\/span>1<\/b><\/span><\/span><\/sub><\/span>\u00a0vale 6 A.<\/b><\/span><\/span><\/span><\/p>\n

II. O sentido da corrente que passa pelo resistor R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0\u00e9 da esquerda para a direita.<\/b><\/span><\/span><\/span><\/p>\n

III. A pot\u00eancia dissipada no resistor R<\/b><\/span><\/span><\/span>2<\/b><\/span><\/span><\/sub><\/span>\u00a0vale 12 W.<\/b><\/span><\/span><\/span><\/p>\n

IV. O sentido da corrente que passa pelo resistor R \u00e9 de cima para baixo.<\/b><\/span><\/span><\/span><\/p>\n

Est\u00e3o CORRETAS<\/b><\/span><\/span><\/span><\/p>\n

A) I, II, III e IV. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

B) II, III e IV. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

C) I, II e III. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

D) II e IV. \u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0\u00a0<\/b><\/span><\/span><\/span><\/p>\n

E) I, III e IV.<\/b><\/span><\/span><\/span><\/p>\n

 <\/p>\n

Confira o gabarito e a resolu\u00e7\u00e3o comentada<\/span><\/a><\/h3>\n","protected":false},"excerpt":{"rendered":"

Exerc\u00edcios de vestibulares com resolu\u00e7\u00e3o comentada sobre Circuitos Compostos 01-(UFU-MG) Considera o trecho de um circuito el\u00e9trico apresentado a seguir, contendo um resistor R, um gerador de for\u00e7a eletromotriz E e um fio ideal AB. Os pontos A, C e D n\u00e3o se ligam diretamente no circuito. \u00c9 correto afirmar que a) a pot\u00eancia dissipada no resistor R depende, diretamente,<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":1862,"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-1864","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1864","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=1864"}],"version-history":[{"count":3,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1864\/revisions"}],"predecessor-version":[{"id":10518,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1864\/revisions\/10518"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/1862"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=1864"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}