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Apostila de Eletrotc..

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Exercícios<br />

R.14: Qual a energia armazenada num capacitor <strong>de</strong> 4µF, quando carregado com uma<br />

carga <strong>de</strong> 20 µC?<br />

Solução: Calcula-se, <strong>de</strong> início, a tensão entre as placas:<br />

Q = C × V<br />

⇒<br />

SENAI/SC<br />

Eletrotécnica<br />

20 = 4×<br />

V<br />

20<br />

V =<br />

4<br />

⇒ V = 5V<br />

A energia armazenada será:<br />

1 2<br />

E =<br />

× C × V<br />

2<br />

E = 50µJ<br />

⇒<br />

1<br />

E =<br />

2<br />

× 4×<br />

25<br />

30

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