** Problem + Hard 3.1**
Source: Problem 6.24 - page 216 - SADIKU, Matthew N. O. , ALEXANDER, Charles K. - Book: Fundamentals of Electric Circuits - McGraw Hill - 5th edition - 2013.

Knowing that _{1} = 30 µF_{2} = 60 µF_{3} = 14 µF_{4} = 20 µF_{5} = 80 µF

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** Problem + Hard 3.2**
Source: Problem 6.23 - page 243 - IRWIN, J. David - Book: Circuit Analysis in Engineering - 4th edition - Ed. pearson - 2013.

If the voltage at terminals

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** Problem + Hard 3.3**
Source: Problem 25-28 - pag 135 - HALLIDAY, RESNICK,
WALKER, Jearl - Book: Fundamentals of Physics - Vol 3 - Ed. LTC - 8th edition - 2009.

The capacitor _{3}_{1}_{1}_{3}_{3}_{1}_{1}_{3} → ∞.

_{1}_{2}

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