{"id":3316,"date":"2017-10-01T14:13:24","date_gmt":"2017-10-01T14:13:24","guid":{"rendered":"http:\/\/fisicaevestibular.com.br\/novo\/?page_id=3316"},"modified":"2024-06-30T00:14:11","modified_gmt":"2024-06-30T00:14:11","slug":"eletrostatica-2017-2016-2015","status":"publish","type":"page","link":"https:\/\/fisicaevestibular.com.br\/novo\/vestibulares-recentes\/eletricidade\/eletrostatica-2017-2016-2015\/","title":{"rendered":"Eletrost\u00e1tica – 2017 – 2016 – 2015"},"content":{"rendered":"

Vestibulares Recentes \u2013 Eletricidade<\/span><\/span><\/span><\/h2>\n

2017 \u2013 2016 – 2015<\/span><\/span><\/span><\/h2>\n

ELETROST\u00c1TICA<\/span><\/span><\/span><\/p>\n

Carga el\u00e9trica e Processos de eletriza\u00e7\u00e3o<\/span><\/span><\/span><\/p>\n

01-(UEMG-MG-015)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\u201c<\/span>Tenho que estudar melhor<\/b><\/span><\/span><\/span><\/span><\/p>\n

O caso das part\u00edculas de el\u00e9tron<\/b><\/span><\/span><\/span><\/span><\/p>\n

Que est\u00e3o sem ser<\/b><\/span><\/span><\/span><\/span><\/p>\n

E s\u00e3o sem estar.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Que o n\u00facleo existe<\/b><\/span><\/span><\/span><\/span><\/p>\n

\u00e9 certo.\u201d<\/b><\/span><\/span><\/span><\/span><\/p>\n

(S\u00edsifo desce a montanha, \u201cN\u00e3o Lugar\u201d.)<\/b><\/span><\/span><\/span><\/span><\/p>\n

Tr\u00eas alunos<\/b><\/span><\/span>,\u00a0inspirados pelos versos de Affonso Romano, fizeram os seguintes coment\u00e1rios:<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Coment\u00e1rio 1:<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>el\u00e9trons s\u00e3o part\u00edculas com massa. F\u00f3tons, que s\u00e3o part\u00edculas de luz, n\u00e3o t\u00eam massa.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Coment\u00e1rio 2:<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>um el\u00e9tron pode emitir um f\u00f3ton e voltar a um n\u00edvel mais pr\u00f3ximo ao n\u00facleo.\u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

Esse f\u00f3ton emitido corresponde a uma onda eletromagn\u00e9tica.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Coment\u00e1rio 3:<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>O n\u00facleo de um \u00e1tomo \u00e9 constitu\u00eddo de pr\u00f3tons, n\u00eautrons e el\u00e9trons, que, ligados, mant\u00eam a neutralidade do \u00e1tomo.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Est\u00e1(\u00e3o)\u00a0<\/b><\/span><\/span>CORRETO(S)<\/b><\/span><\/span><\/span><\/span><\/p>\n

A)<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>apenas os coment\u00e1rios 1 e 2.<\/b><\/span><\/span><\/span><\/span><\/p>\n

B<\/b><\/span><\/span>)\u00a0apenas o coment\u00e1rio 3.<\/b><\/span><\/span><\/span><\/span><\/p>\n

C)<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>apenas os coment\u00e1rios 2 e 3.<\/b><\/span><\/span><\/span><\/span><\/p>\n

D)<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>apenas o coment\u00e1rio 1.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

02-(FGV-SP-015)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Deseja-se\u00a0<\/b><\/span><\/span>eletrizar um objeto met\u00e1lico, inicialmente neutro<\/b><\/span><\/span>, <\/b><\/span><\/span>pelos processos de eletriza\u00e7\u00e3o<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

conhecidos, e\u00a0<\/b><\/span><\/span>obter uma quantidade de carga negativa de 3,2\u00a0\u03bcC. <\/b><\/span><\/span><\/span><\/span><\/p>\n

Sabendo-se que a\u00a0<\/b><\/span><\/span>carga elementar vale 1,6\u00b710-19\u00a0C, para se conseguir a eletriza\u00e7\u00e3o desejada ser\u00e1 preciso<\/b><\/span><\/span><\/span><\/span><\/p>\n

(A)<\/b><\/span><\/span>\u00a0<\/b><\/span>retirar\u00a0<\/b><\/span><\/span>do objeto 20 trilh\u00f5es de pr\u00f3tons<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(B)<\/b><\/span><\/span>\u00a0<\/b><\/span>retirar<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>do objeto 20 trilh\u00f5es de el\u00e9trons.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(C)<\/b><\/span><\/span>\u00a0<\/b><\/span>acrescentar<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>ao objeto 20 trilh\u00f5es de el\u00e9trons.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(D)<\/b><\/span><\/span>\u00a0<\/b><\/span>acrescentar<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>ao objeto cerca de 51 trilh\u00f5es de el\u00e9trons.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(E)<\/b><\/span><\/span>\u00a0<\/b><\/span>retirar<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>do objeto cerca de 51 trilh\u00f5es de pr\u00f3tons.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

03-(Faculdade de Tecnologia Termomec\u00e2nica \u2013 SP- 017)\"\"<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Analise a imagem na qual se v\u00ea uma sequ\u00eancia de eletriza\u00e7\u00e3o por contato entre <\/b><\/span><\/span>dois <\/b><\/span><\/span>condutores A e B <\/b><\/span><\/span>feitos com o mesmo material<\/b><\/span><\/span>, mas de\u00a0<\/b><\/span><\/span>tamanhos diferentes<\/b><\/span><\/span>, sendo\u00a0<\/b><\/span><\/span>inicialmente A neutro e B eletricamente positivo<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Os corpos A e B, ap\u00f3s o contato, s\u00e3o levados a uma posi\u00e7\u00e3o tal que <\/b><\/span><\/span>efeitos de indu\u00e7\u00e3o passam a ser desprez\u00edveis<\/b><\/span><\/span>. O resultado final \u00e9:<\/b><\/span><\/span><\/span><\/span><\/p>\n

(A) A e B ficam carregados com sinais contr\u00e1rios.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(B) A e B ficam carregados positivamente, mas em quantidades desiguais de cargas.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(C) A fica positivamente carregado, e B se neutraliza.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(D) A e B ficam carregados positivamente e com a mesma quantidade de carga.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(E) A permanece neutro, e B permanece carregado positivamente.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

04-(PUC-SP-015)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Por meio do\u00a0<\/b><\/span><\/span>processo<\/b><\/span><\/span>\u00a0conhecido como\u00a0<\/b><\/span><\/span>eletriza\u00e7\u00e3o por atrito\u00a0<\/b><\/span><\/span>eletriza-se com um\u00a0<\/b><\/span><\/span>tecido<\/b><\/span><\/span>\u00a0uma\u00a0<\/b><\/span><\/span>pequena esfera met\u00e1lica<\/b><\/span><\/span>,\u00a0<\/b><\/span><\/span>inicialmente neutra\u00a0<\/b><\/span><\/span>e presa a um suporte isolante.\u00a0<\/b><\/span><\/span>Ap\u00f3s o atrito<\/b><\/span><\/span>, constata-se que essa esfera\u00a0<\/b><\/span><\/span>perdeu 1,0.10<\/b><\/span><\/span>20<\/b><\/span><\/sup><\/span>\u00a0el\u00e9trons.<\/b><\/span><\/span><\/span><\/span><\/p>\n

A seguir, faz-se o\u00a0<\/b><\/span><\/span>contato imediato e sucessivo dessa esfera com outras tr\u00eas (3) esferas id\u00eanticas\u00a0<\/b><\/span><\/span>a ela,\u00a0<\/b><\/span><\/span>inicialmente neutras<\/b><\/span><\/span>, fixadas em suportes isolantes e\u00a0<\/b><\/span><\/span>separadas entre si\u00a0<\/b><\/span><\/span>conforme mostra a figura.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Depois dos contatos<\/b><\/span><\/span>, a\u00a0<\/b><\/span><\/span>esfera inicialmente eletrizada por atrito\u00a0<\/b><\/span><\/span>\u00e9 levada para bem longe das demais. Supondo o local do experimento eletricamente isolado,\u00a0<\/b><\/span><\/span>k a constante eletrost\u00e1tica do meio do local\u00a0<\/b><\/span><\/span>do experimento e o potencial de refer\u00eancia no infinito igual a zero,\u00a0<\/b><\/span><\/span>determine o potencial el\u00e9trico no ponto C devido \u00e0s cargas das esferas fixas.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Dado:\u00a0<\/b><\/span><\/span>carga do el\u00e9tron=1,6.10-19C<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

05-(COL\u00c9GIO NAVAL \u2013 2016\/17)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Com\u00a0<\/b><\/span><\/span>rela\u00e7\u00e3o<\/b><\/span><\/span>\u00a0\u00e0\u00a0<\/b><\/span><\/span>eletricidade e ao magnetismo,\u00a0<\/b><\/span><\/span>assinale a\u00a0<\/b><\/span><\/span>op\u00e7\u00e3o\u00a0INCORRETA.\u00a0<\/b><\/span><\/span>
\n<\/b><\/span><\/span>a)\u00a0Corpos isolantes\u00a0<\/b><\/span><\/span>apresentam\u00a0<\/b><\/span><\/span>pouca quantidade de el\u00e9trons livres\u00a0<\/b><\/span><\/span>e, por isso, podem ser\u00a0<\/b><\/span><\/span>facilmente eletrizados.\u00a0\u00a0\u00a0<\/b><\/span><\/span>
\n<\/b><\/span><\/span>b)\u00a0Corpos condutores\u00a0<\/b><\/span><\/span>apresentam\u00a0<\/b><\/span><\/span>grande quantidade de el\u00e9trons livres\u00a0<\/b><\/span><\/span>e, por isso, apresentam\u00a0<\/b><\/span><\/span>grande dificuldade para serem eletrizados.\u00a0\u00a0\u00a0<\/b><\/span><\/span>
\n<\/b><\/span><\/span>c)\u00a0<\/b><\/span><\/span>A\u00a0<\/b><\/span><\/span>for\u00e7a el\u00e9trica entre dois corpos eletrizados\u00a0<\/b><\/span><\/span>pode ser\u00a0<\/b><\/span><\/span>atrativa ou repulsiva, <\/b><\/span><\/span>dependendo apenas da\u00a0<\/b><\/span><\/span>carga el\u00e9trica dos corpos.\u00a0\u00a0\u00a0<\/b><\/span><\/span>
\n<\/b><\/span><\/span>d)\u00a0<\/b><\/span><\/span>A\u00a0<\/b><\/span><\/span>passagem da corrente el\u00e9trica por um fio condutor\u00a0<\/b><\/span><\/span>produz um\u00a0<\/b><\/span><\/span>campo magn\u00e9tico em volta desse fio, que pode ser verificado pela presen\u00e7a de uma b\u00fassola.\u00a0\u00a0\u00a0<\/b><\/span><\/span>
\n<\/b><\/span><\/span>e)\u00a0<\/b><\/span><\/span>Os\u00a0<\/b><\/span><\/span>motores el\u00e9tricos funcionam devido ao aparecimento de for\u00e7as\u00a0<\/b><\/span><\/span>de\u00a0<\/b><\/span><\/span>origem mec\u00e2nica, cujo movimento deve-se \u00e0 passagem de corrente el\u00e9trica pelo seu interior.\u00a0\u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

06-<\/span><\/span><\/span>(FUVEST-SP-017)<\/b><\/span><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

a)<\/b><\/span><\/span>\u00a0zero\u00a0<\/b><\/span><\/span>e<\/b><\/span><\/span>\u00a0zero.<\/b><\/span><\/span><\/span><\/span><\/p>\n

b)<\/b><\/span><\/span>\u00a0zero\u00a0<\/b><\/span><\/span>e<\/b><\/span><\/span>\u00a0\u2013 5,0.10<\/b><\/span><\/span>-12<\/b><\/span><\/sup><\/span>\u00a0C.<\/b><\/span><\/span><\/span><\/span><\/p>\n

c)<\/b><\/span><\/span>\u00a0\u2013 2,5.10<\/b><\/span><\/span>-12<\/b><\/span><\/sup><\/span>\u00a0\u00a0C\u00a0<\/b><\/span><\/span>e<\/b><\/span><\/span>\u00a0\u2013 2,5.10<\/b><\/span><\/span>-12<\/b><\/span><\/sup><\/span>\u00a0\u00a0C.<\/b><\/span><\/span><\/span><\/span><\/p>\n

d)<\/b><\/span><\/span>\u00a0\u2013 2,5.10<\/b><\/span><\/span>-12<\/b><\/span><\/sup><\/span>\u00a0\u00a0C\u00a0<\/b><\/span><\/span>e<\/b><\/span><\/span>\u00a0+ 2,5.10<\/b><\/span><\/span>-12<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span><\/span>\u00a0<\/b><\/span><\/span>C.<\/b><\/span><\/span><\/span><\/span><\/p>\n

e)<\/b><\/span><\/span>\u00a0+ 5,0.10<\/b><\/span><\/span>-12<\/b><\/span><\/sup><\/span>\u00a0\u00a0C\u00a0<\/b><\/span><\/span>e<\/b><\/span><\/span>\u00a0zero.<\/b><\/span><\/span><\/span><\/span><\/p>\n

For\u00e7a el\u00e9trica \u2013 Lei de Coulomb<\/span><\/span><\/span><\/p>\n

07-(UNIFESP-SP-015)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma\u00a0<\/b><\/span><\/span>carga el\u00e9trica puntiforme Q > 0 est\u00e1 fixa<\/b><\/span><\/span>\u00a0em uma regi\u00e3o do espa\u00e7o e <\/b><\/span><\/span>cria um campo el\u00e9trico ao seu redor.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Outra\u00a0<\/b><\/span><\/span>carga el\u00e9trica puntiforme q<\/b><\/span><\/span>, tamb\u00e9m positiva, \u00e9 colocada em <\/b><\/span><\/span>determinada posi\u00e7\u00e3o desse campo el\u00e9trico<\/b><\/span><\/span>, podendo\u00a0<\/b><\/span><\/span>mover-se dentro dele<\/b><\/span><\/span>.\u00a0<\/b><\/span><\/span>A malha quadriculada <\/b><\/span><\/span>representada na figura est\u00e1 contida em um plano xy, que tamb\u00e9m\u00a0<\/b><\/span><\/span>cont\u00e9m as cargas.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Quando na\u00a0<\/b><\/span><\/span>posi\u00e7\u00e3o A, q fica sujeita a uma for\u00e7a eletrost\u00e1tica de m\u00f3dulo F exercida por Q.<\/b><\/span><\/span><\/span><\/span><\/p>\n

a) Calcule o\u00a0<\/b><\/span><\/span>m\u00f3dulo da for\u00e7a eletrost\u00e1tica entre Q e q, em fun\u00e7\u00e3o apenas de F<\/b><\/span><\/span>, quando\u00a0<\/b><\/span><\/span>q estiver na posi\u00e7\u00e3o B.<\/b><\/span><\/span><\/span><\/span><\/p>\n

b) Adotando\u00a0<\/b><\/span><\/span>\u221a2 = 1,4<\/b><\/span><\/span>\u00a0e sendo\u00a0<\/b><\/span><\/span>K a constante eletrost\u00e1tica<\/b><\/span><\/span>\u00a0do meio onde se encontram as cargas, calcule o\u00a0<\/b><\/span><\/span>trabalho realizado pela for\u00e7a el\u00e9trica quando a carga q \u00e9 transportada de A para B.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

08-(UDESC-SC-016)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

Duas\u00a0<\/b><\/span><\/span>pequenas esferas est\u00e3o separadas por uma dist\u00e2ncia de 30 cm<\/b><\/span><\/span>. As duas esferas\u00a0<\/b><\/span><\/span>repelem-se<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

com uma\u00a0<\/b><\/span><\/span>for\u00e7a de 7,5 \u00d7 10<\/b><\/span><\/span>-6<\/b><\/span><\/sup><\/span>\u00a0N<\/b><\/span><\/span>. Considerando que a\u00a0<\/b><\/span><\/span>carga el\u00e9trica das duas esferas \u00e9 20 nC,<\/b><\/span><\/span>\u00a0a\u00a0<\/b><\/span><\/span>carga el\u00e9trica de cada esfera<\/b><\/span><\/span>\u00a0\u00e9, respectivamente:<\/b><\/span><\/span><\/span><\/span><\/p>\n

A.<\/b><\/span><\/span>\u00a0( ) 10 nC e 10 nC<\/b><\/span><\/span><\/span><\/span><\/p>\n

B.<\/b><\/span><\/span>\u00a0( ) 13 nC e 7 nC<\/b><\/span><\/span><\/span><\/span><\/p>\n

C.<\/b><\/span><\/span>\u00a0( ) 7,5 nC e 10 nC<\/b><\/span><\/span><\/span><\/span><\/p>\n

D.<\/b><\/span><\/span>\u00a0( ) 12 nC e 8 nC<\/b><\/span><\/span><\/span><\/span><\/p>\n

E.<\/b><\/span><\/span>\u00a0( ) 15 nC e 5 nC<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

 <\/p>\n

09-(Mackenzie-SP-016)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n

Dois corpos eletrizados com cargas el\u00e9tricas\u00a0<\/b><\/span><\/span>puntiformes<\/b><\/span><\/span>\u00a0<\/b><\/span>+Q<\/b><\/span><\/span>\u00a0e\u00a0<\/b><\/span><\/span>\u2013Q<\/b><\/span><\/span>\u00a0s\u00e3o colocados sobre o\u00a0<\/b><\/span><\/span>eixo x<\/b><\/span><\/span>\u00a0nas posi\u00e7\u00f5es\u00a0<\/b><\/span><\/span>+x<\/b><\/span><\/span>\u00a0e\u00a0<\/b><\/span><\/span>\u2013x<\/b><\/span><\/span>, respectivamente. Uma<\/b><\/span><\/span>carga el\u00e9trica<\/b><\/span><\/span>\u00a0de prova\u00a0<\/b><\/span><\/span>\u2013q<\/b><\/span><\/span>\u00a0\u00e9 colocada sobre o\u00a0<\/b><\/span><\/span>eixo y<\/b><\/span><\/span>\u00a0na posi\u00e7\u00e3o\u00a0<\/b><\/span><\/span>+y<\/b><\/span><\/span>, como mostra a figura acima. A\u00a0<\/b><\/span><\/span>for\u00e7a eletrost\u00e1tica resultante\u00a0<\/b><\/span><\/span>sobre a carga el\u00e9trica de prova.<\/b><\/span><\/span><\/span><\/span>\"\"<\/p>\n

a) tem dire\u00e7\u00e3o horizontal e sentido da esquerda para a direita.<\/b><\/span><\/span><\/span><\/span><\/p>\n

b) tem dire\u00e7\u00e3o horizontal e sentido da direita para a esquerda.<\/b><\/span><\/span><\/span><\/span><\/p>\n

c) tem dire\u00e7\u00e3o vertical e sentido ascendente.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

10-(Medicina \u2013 EMESCAM \u2013 ES \u2013 017)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

11-(FUVEST-SP-016)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Os\u00a0<\/b><\/span><\/span>centros de quatro esferas id\u00eanticas, I, II, III e IV,<\/b><\/span><\/span>\u00a0com\u00a0<\/b><\/span><\/span>distribui\u00e7\u00f5es uniformes de carga<\/b><\/span><\/span>, formam um\u00a0<\/b><\/span><\/span>quadrado.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

a)<\/b><\/span><\/span>\u00a0+Q, \u2013Q, \u2013Q, +Q<\/b><\/span><\/span><\/span><\/span><\/p>\n

b)<\/b><\/span><\/span>\u00a0+2Q, \u2013Q, +Q, \u20132Q<\/b><\/span><\/span><\/span><\/span><\/p>\n

c)<\/b><\/span><\/span>\u00a0+Q, +Q, \u2013Q, \u2013Q<\/b><\/span><\/span><\/span><\/span><\/p>\n

d)<\/b><\/span><\/span>\u00a0\u2013Q, \u2013Q, +Q, +Q<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n

Campo El\u00e9trico<\/span><\/span><\/span><\/p>\n

12-(FUVEST-SP-015)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Em uma aula de\u00a0<\/b><\/span><\/span>laborat\u00f3rio de F\u00edsica<\/b><\/span><\/span>, para estudar\u00a0<\/b><\/span><\/span>propriedades de cargas el\u00e9tricas<\/b><\/span><\/span>, foi realizado um<\/b><\/span><\/span> <\/b>experimento em que\u00a0<\/b><\/span><\/span>pequenas esferas eletrizadas s\u00e3o injetadas na parte superior de uma c\u00e2mara,<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

em v\u00e1cuo<\/b><\/span><\/span>, onde h\u00e1 um\u00a0<\/b><\/span><\/span>campo el\u00e9trico uniforme na mesma dire\u00e7\u00e3o e sentido da acelera\u00e7\u00e3o local da gravidade.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Observou-se que<\/b><\/span><\/span>, com\u00a0<\/b><\/span><\/span>campo el\u00e9trico<\/b><\/span><\/span>\u00a0de m\u00f3dulo igual a\u00a0<\/b><\/span><\/span>2.10<\/b><\/span><\/span>3<\/b><\/span><\/sup><\/span>\u00a0V\/m<\/b><\/span><\/span>,\u00a0<\/b><\/span><\/span>uma das esferas, de\u00a0<\/b><\/span><\/span>massa 3,2.<\/b><\/span><\/span>\u00a0<\/b><\/span>10-15\u00a0kg<\/b><\/span><\/span>\u00a0permanecia com\u00a0<\/b><\/span><\/span>velocidade constante<\/b><\/span><\/span>\u00a0no interior da c\u00e2mara.\u00a0<\/b><\/span><\/span>Essa esfera tem<\/b><\/span><\/span><\/span><\/span><\/p>\n

a)<\/b><\/span><\/span>\u00a0<\/b><\/span>o mesmo n\u00famero de el\u00e9trons e de pr\u00f3tons<\/b><\/span><\/span>.\u00a0<\/b><\/span><\/span><\/span><\/span><\/p>\n

b)<\/b><\/span><\/span>\u00a0<\/b><\/span>100 el\u00e9trons a mais que pr\u00f3tons.<\/b><\/span><\/span><\/span><\/span><\/p>\n

c)<\/b><\/span><\/span>\u00a0<\/b><\/span>100 el\u00e9trons a menos que pr\u00f3tons<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

d)<\/b><\/span><\/span>\u00a0<\/b><\/span>2000 el\u00e9trons a mais que pr\u00f3tons.<\/b><\/span><\/span><\/span><\/span><\/p>\n

e)<\/b><\/span><\/span>\u00a0<\/b><\/span>2000 el\u00e9trons a menos que pr\u00f3tons.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n

13-<\/span><\/span><\/span>(FAMERP-SP-017)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Quatro cargas el\u00e9tricas<\/b><\/span><\/span>\u00a0puntiformes,\u00a0<\/b><\/span><\/span>Q1, Q2, Q3\u00a0e Q4,\u00a0<\/b><\/span><\/span>est\u00e3o\u00a0<\/b><\/span><\/span>fixas nos v\u00e9rtices de um quadrado,\u00a0<\/b><\/span><\/span>de modo que\u00a0<\/b><\/span><\/span>|Q1| = |Q2| = |Q3| = |Q4|.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

As\u00a0<\/b><\/span><\/span>posi\u00e7\u00f5es das cargas e seus respectivos sinais est\u00e3o indicados na figura.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Se\u00a0<\/b><\/span><\/span>E<\/b><\/span><\/span>\u00a0for o\u00a0<\/b><\/span><\/span>m\u00f3dulo do campo el\u00e9trico no ponto P, centro<\/b><\/span><\/span>\u00a0do quadrado,\u00a0<\/b><\/span><\/span>devido \u00e0 carga Q1,\u00a0<\/b><\/span><\/span>o\u00a0<\/b><\/span><\/span>campo el\u00e9trico resultante no ponto P, devido \u00e0 presen\u00e7a das quatro cargas,\u00a0<\/b><\/span><\/span>ter\u00e1 m\u00f3dulo<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n

14-(FPS-Faculdade Pernambucana de Sa\u00fade-PE-2017)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

15-(UNESP-SP-017)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

16-(Escola Naval \u2013 015\/016)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Analise<\/b><\/span><\/span>\u00a0a figura abaixo.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Duas\u00a0<\/b><\/span><\/span>cargas puntiformes desconhecidas (Q0\u00a0, Q1)<\/b><\/span><\/span>\u00a0est\u00e3o\u00a0<\/b><\/span><\/span>fixas\u00a0<\/b><\/span><\/span>em pontos distantes,\u00a0<\/b><\/span><\/span>d0\u00a0e d1, do ponto P,<\/b><\/span><\/span>\u00a0localizado sobre a\u00a0<\/b><\/span><\/span>reta\u00a0<\/b><\/span><\/span>que une as cargas<\/b><\/span><\/span>(ver figura).<\/b><\/span><\/span><\/span><\/span><\/p>\n

Supondo que, se um\u00a0<\/b><\/span><\/span>el\u00e9tron<\/b><\/span><\/span>\u00a0\u00e9 cuidadosamente\u00a0<\/b><\/span><\/span>colocado em P e liberado do\u00a0repouso,<\/b><\/span><\/span>\u00a0ele se\u00a0<\/b><\/span><\/span>desloca para direita<\/b><\/span><\/span>\u00a0(no sentido da carga\u00a0Q1), sendo assim, pode-se afirmar que, se\u00a0<\/b><\/span><\/span>Qo\u00a0e Qi<\/b><\/span><\/span><\/span><\/span><\/p>\n

(A)<\/b><\/span><\/span>\u00a0s\u00e3o\u00a0<\/b><\/span><\/span>positivas, ent\u00e3o\u00a0dl\u00a0< d0.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(B)<\/b><\/span><\/span>s\u00e3o\u00a0<\/b><\/span><\/span>negativas, ent\u00e3o do\u00a0< d1.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(C)<\/b><\/span><\/span>\u00a0t\u00eam\u00a0<\/b><\/span><\/span>sinais contr\u00e1rios, Q1\u00a0\u00e9 a carga negativa.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(D)<\/b><\/span><\/span>\u00a0t\u00eam\u00a0<\/b><\/span><\/span>sinais contr\u00e1rios, Qo\u00a0\u00e9 a carga positiva.<\/b><\/span><\/span><\/span><\/span><\/p>\n

(E)<\/b><\/span><\/span>\u00a0<\/b><\/span>t\u00eam o mesmo sinal,<\/b><\/span><\/span>\u00a0o\u00a0<\/b><\/span><\/span>campo el\u00e9trico resultante<\/b><\/span><\/span>\u00a0em P\u00a0aponta para a <\/b><\/span><\/span>esquerda.<\/b><\/span><\/span><\/span><\/span><\/p>\n

Linhas de for\u00e7a (de campo) \u2013 Potencial eletrost\u00e1tico<\/span><\/span><\/span><\/p>\n

 <\/p>\n

17-<\/span><\/span><\/span>(UNESP-SP-017)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

Trabalho da for\u00e7a eletrost\u00e1tica<\/span><\/span><\/span><\/p>\n

 <\/p>\n

 <\/p>\n

18-(FUVEST-SP-015)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A\u00a0<\/b><\/span><\/span>regi\u00e3o entre duas placas met\u00e1licas, planas e paralelas<\/b><\/span><\/span>\u00a0est\u00e1 esquematizada na figura abaixo.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

As\u00a0<\/b><\/span><\/span>linhas tracejadas<\/b><\/span><\/span>\u00a0representam o\u00a0<\/b><\/span><\/span>campo el\u00e9trico uniforme<\/b><\/span><\/span>\u00a0existente <\/b><\/span><\/span>entre as placas.<\/b><\/span><\/span>\u00a0A\u00a0<\/b><\/span><\/span>dist\u00e2ncia\u00a0<\/b><\/span><\/span>entre as placas \u00e9\u00a0<\/b><\/span><\/span>5 mm<\/b><\/span><\/span>\u00a0e a\u00a0<\/b><\/span><\/span>diferen\u00e7a de potencial<\/b><\/span><\/span>\u00a0entre elas \u00e9\u00a0<\/b><\/span><\/span>300 V.<\/b><\/span><\/span>\u00a0As\u00a0<\/b><\/span><\/span>coordenadas dos pontos\u00a0<\/b><\/span><\/span>A, B<\/b><\/span><\/span>\u00a0e\u00a0<\/b><\/span><\/span>C\u00a0<\/b><\/span><\/span>s\u00e3o <\/b><\/span><\/span>mostradas na figura.<\/b><\/span><\/span>\u00a0Determine<\/b><\/span><\/span><\/span><\/span><\/p>\n

a)<\/b><\/span><\/span>\u00a0os\u00a0<\/b><\/span><\/span>m\u00f3dulos EA, EB\u00a0e EC<\/b><\/span><\/span>\u00a0<\/b><\/span>do\u00a0<\/b><\/span><\/span>campo el\u00e9trico<\/b><\/span><\/span>\u00a0nos pontos\u00a0<\/b><\/span><\/span>A, B e C, respectivamente;<\/b><\/span><\/span><\/span><\/span><\/p>\n

b)<\/b><\/span><\/span>\u00a0as\u00a0<\/b><\/span><\/span>diferen\u00e7as de potencial VAB\u00a0e VBC<\/b><\/span><\/span>\u00a0entre os\u00a0<\/b><\/span><\/span>pontos A e B e entre os pontos B e C,<\/b><\/span><\/span><\/span><\/span><\/p>\n

respectivamente;<\/b><\/span><\/span><\/span><\/span><\/p>\n

c)<\/b><\/span><\/span>\u00a0o\u00a0<\/b><\/span><\/span>trabalho W<\/b><\/span><\/span>\u00a0realizado pela\u00a0<\/b><\/span><\/span>for\u00e7a el\u00e9trica<\/b><\/span><\/span>\u00a0sobre um\u00a0<\/b><\/span><\/span>el\u00e9tron<\/b><\/span><\/span>\u00a0que se desloca do\u00a0<\/b><\/span><\/span>ponto C ao ponto A.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

19-(MACKENZIE-SP-015)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma\u00a0<\/b><\/span><\/span>carga el\u00e9trica de<\/b><\/span><\/span>\u00a0<\/b><\/span>intensidade Q = 10,0 \u03bcC<\/b><\/span><\/span>,\u00a0<\/b><\/span><\/span>no v\u00e1cuo<\/b><\/span><\/span>, gera um\u00a0<\/b><\/span><\/span>campo el\u00e9trico<\/b><\/span><\/span>\u00a0<\/b><\/span>em dois pontos\u00a0<\/b><\/span><\/span>A e<\/b><\/span><\/span>\u00a0<\/b><\/span>B<\/b><\/span><\/span>, conforme figura abaixo<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Sabendo-se que a\u00a0<\/b><\/span><\/span>constante eletrost\u00e1tica do v\u00e1cuo \u00e9 ko\u00a0= 9.10<\/b><\/span><\/span>9<\/b><\/span><\/sup><\/span>\u00a0Nm<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\/C<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\u00a0<\/b><\/span>o <\/b><\/span><\/span>trabalho realizado pela for\u00e7a el\u00e9trica<\/b><\/span><\/span>\u00a0para transferir uma\u00a0<\/b><\/span><\/span>carga q= 2,00 \u03bcC do ponto B at\u00e9 o ponto A \u00e9, em mJ,\u00a0<\/b><\/span><\/span>igual a<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n

20-<\/span><\/span><\/span>(UERR-RR-017)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Uma\u00a0<\/b><\/span><\/span>carga el\u00e9trica puntiforme de 1,2 \u00b5C move-se entre os pontos A e B\u00a0<\/b><\/span><\/span>de um\u00a0<\/b><\/span><\/span>campo el\u00e9trico.\u00a0<\/b><\/span><\/span>Sabendo que o\u00a0<\/b><\/span><\/span>potencial el\u00e9trico no ponto A \u00e9 VA\u00a0= 10 V\u00a0<\/b><\/span><\/span>e no\u00a0<\/b><\/span><\/span>ponto B \u00e9 VB\u00a0= 3 V,\u00a0<\/b><\/span><\/span>podemos afirmar que o\u00a0<\/b><\/span><\/span>trabalho realizado pela for\u00e7a el\u00e9trica durante esse transporte<\/b><\/span><\/span>\u00a0foi de:<\/b><\/span><\/span><\/span><\/span><\/p>\n

A)\u00a0<\/b><\/span><\/span>8,4 x 10<\/b><\/span><\/span>-5<\/b><\/span><\/sup><\/span>\u00a0J<\/b><\/span><\/span><\/span><\/span><\/p>\n

B)\u00a0<\/b><\/span><\/span>8,4 J<\/b><\/span><\/span><\/span><\/span><\/p>\n

C)\u00a0<\/b><\/span><\/span>8,4 \u00b5J<\/b><\/span><\/span><\/span><\/span><\/p>\n

D)\u00a0<\/b><\/span><\/span>30,6 x 10<\/b><\/span><\/span>-6<\/b><\/span><\/sup><\/span>\u00a0J<\/b><\/span><\/span><\/span><\/span><\/p>\n

E)\u00a0<\/b><\/span><\/span>30,6 J<\/b><\/span><\/span><\/span><\/span><\/p>\n

21-(UERR-RR-017)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A\u00a0<\/b><\/span><\/span>diferen\u00e7a de potencial entre dois pontos A e B,\u00a0<\/b><\/span><\/span>localizados respectivamente a\u00a0<\/b><\/span><\/span>5 cm e 9 cm de uma carga el\u00e9trica Q de carga 7 \u00b5C, <\/b><\/span><\/span>situada no v\u00e1cuo\u00a0<\/b><\/span><\/span>(k = 9.10<\/b><\/span><\/span>9<\/b><\/span><\/sup><\/span>\u00a0Nm<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\/C<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>),\u00a0<\/b><\/span><\/span>\u00e9 dada por:<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

 <\/p>\n

22-(UFAM-AM-2017)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

A\u00a0<\/b><\/span><\/span>figura a seguir<\/b><\/span><\/span>\u00a0mostra a\u00a0<\/b><\/span><\/span>configura\u00e7\u00e3o das linhas de for\u00e7a\u00a0<\/b><\/span><\/span>e de\u00a0<\/b><\/span><\/span>duas superf\u00edcies equipotenciais\u00a0<\/b><\/span><\/span>de um\u00a0<\/b><\/span><\/span>campo el\u00e9trico uniforme de intensidade <\/b><\/span><\/span>E<\/b><\/span><\/span>\u00a0= 5\u00d710<\/b><\/span><\/span>2<\/b><\/span><\/sup><\/span>\u00a0V\/m<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Se uma\u00a0<\/b><\/span><\/span>carga puntiforme\u00a0<\/b><\/span><\/span>q<\/b><\/span><\/span>\u00a0= +0,1\u00a0<\/b><\/span><\/span>\u00b5C<\/b><\/span><\/span>\u00a0\u00e9 colocada no ponto A,\u00a0<\/b><\/span><\/span>assinale a <\/b><\/span><\/span>alternativa INCORRETA:<\/b><\/span><\/span><\/span><\/span><\/p>\n

a)\u00a0<\/b><\/span><\/span>O trabalho da for\u00e7a el\u00e9trica que atua na carga puntiforme n\u00e3o depende da trajet\u00f3ria que liga o ponto A com o ponto C e vale 5\u00d710-6\u00a0J.<\/b><\/span><\/span><\/span><\/span><\/p>\n

b)\u00a0<\/b><\/span><\/span>A diferen\u00e7a de potencial el\u00e9trico entre os pontos A e C vale 50\u00a0<\/b><\/span><\/span>J<\/b><\/span><\/span>.<\/b><\/span><\/span><\/span><\/span><\/p>\n

c)\u00a0<\/b><\/span><\/span>Nenhum trabalho \u00e9 realizado pela for\u00e7a el\u00e9trica ao deslocar a carga puntiforme do ponto A para o ponto B.<\/b><\/span><\/span><\/span><\/span><\/p>\n

d)\u00a0<\/b><\/span><\/span>O potencial el\u00e9trico \u00e9 uma grandeza escalar associada a cada ponto do campo el\u00e9trico, de modo que o potencial el\u00e9trico no ponto B \u00e9 maior que o potencial el\u00e9trico no ponto C.<\/b><\/span><\/span><\/span><\/span><\/p>\n

e)\u00a0<\/b><\/span><\/span>O potencial el\u00e9trico \u00e9 uma grandeza vetorial associada a cada ponto do campo el\u00e9trico, de modo que o potencial el\u00e9trico nos pontos A e B tem o mesmo valor<\/b><\/span><\/span><\/span><\/span><\/p>\n

23-(UERJ-RJ-016)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

\"\"<\/p>\n

24-(UDESC-SC-015)<\/b><\/span><\/span><\/span><\/span><\/span><\/p>\n

\"\"<\/p>\n

Ao longo de um\u00a0<\/b><\/span><\/span>processo de aproxima\u00e7\u00e3o de duas part\u00edculas de mesma carga el\u00e9trica<\/b><\/span><\/span>,\u00a0<\/b><\/span><\/span>a energia<\/b><\/span><\/span><\/span><\/span><\/p>\n

\"Eletrost\u00e1tica\"<\/p>\n

potencial el\u00e9trica do sistema:<\/b><\/span><\/span><\/span><\/span><\/p>\n

A.<\/b><\/span><\/span>\u00a0( ) diminui.<\/b><\/span><\/span><\/span><\/span><\/p>\n

B.<\/b><\/span><\/span>\u00a0( ) aumenta<\/b><\/span><\/span><\/span><\/span><\/p>\n

C.<\/b><\/span><\/span>\u00a0( ) aumenta inicialmente e, em seguida, diminui.<\/b><\/span><\/span><\/span><\/span><\/p>\n

D.<\/b><\/span><\/span>\u00a0( ) permanece constante.<\/b><\/span><\/span><\/span><\/span><\/p>\n

E.<\/b><\/span><\/span>\u00a0( ) diminui inicialmente e, em seguida, aumenta.<\/b><\/span><\/span><\/span><\/span><\/p>\n

 <\/p>\n

Confira as resolu\u00e7\u00f5es comentadas<\/span><\/a><\/h3>\n

 <\/p>\n

Clique aqui para ver sobre o tema!<\/a><\/p>\n

Confira as v\u00eddeo aulas!<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Vestibulares Recentes \u2013 Eletricidade 2017 \u2013 2016 – 2015 ELETROST\u00c1TICA Carga el\u00e9trica e Processos de eletriza\u00e7\u00e3o 01-(UEMG-MG-015) \u201cTenho que estudar melhor O caso das part\u00edculas de el\u00e9tron Que est\u00e3o sem ser E s\u00e3o sem estar. Que o n\u00facleo existe \u00e9 certo.\u201d (S\u00edsifo desce a montanha, \u201cN\u00e3o Lugar\u201d.) Tr\u00eas alunos,\u00a0inspirados pelos versos de Affonso Romano, fizeram os seguintes coment\u00e1rios: Coment\u00e1rio 1:\u00a0el\u00e9trons<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":3299,"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-3316","page","type-page","status-publish","hentry"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3316","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=3316"}],"version-history":[{"count":4,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3316\/revisions"}],"predecessor-version":[{"id":9914,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3316\/revisions\/9914"}],"up":[{"embeddable":true,"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/pages\/3299"}],"wp:attachment":[{"href":"https:\/\/fisicaevestibular.com.br\/novo\/wp-json\/wp\/v2\/media?parent=3316"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}