Problem 22-1    Source:   Example 10.9 - page 288 -    BOYLESTAD, Robert L. ,   Book: Introdução à Análise de Circuitos - Ed. Pearson - 10ª edição- 2008.

The capacitor shown in the Figure 22-01.1 has an initial voltage of 4 volts

a) Determine the mathematical expression for the voltage between capacitor terminals once the key is closed.

b)Determine the mathematical expression for the current during the transitional period.

c) Sketch the waveforms of voltage and current from initial value to final.

Problem 22-2    Source:   Problem 10.11 - page 98 -    MARKUS, Otávio - Book: Circuitos Elétricos - CC - CA - Ed. Érica - 9ª edição - 2004.

In the circuit shown in the Figure 22-02.1, V= 12.0 volts , R₁ = R₂ = 10 kΩ , R₃ = 20 kΩ , C₁ = 10 µF , C₂ = C₃ = 20 µF and all capacitors are initially discharged. When the S key is closed calculate:

a) the time constant of the circuit;

b) the minimum time required for the voltage between points a-b to be equal to power supply voltage;

c) the voltage between points a-b for a time equal to half time found in the previous item;

d) the moment the voltage between the points a-b reaches the half of the voltage of the power supply.

Problem 22-3    Source:   Problem 7.13 - page 367 -    THOMAS, Roland E. & ROSA, Albert J. & TOUSSAINT, Gregory J. - Book: The Analysis & Design of Linear Circuits - Ed. John Wiley & Sons, Inc. - 6ª edição - 2009.

In the circuit shown in the Figure 22-03.1, the key has been in position A for a long time. At t = 0 the key is passed to the position B. Determine v_C (t) to t ≥ 0.

Problem 22-4    Source:   Adapted from Exercise 7.12 - page 158 -    NILSSON, James W. & RIEDEL, Susan A. - Book: Circuitos Elétricos - Ed. LTC - 5ª edição - 1999.

In the circuit shown in the Figure 22-04.1, the switch S1 remained closed and the switch S2 open, both for a long time. In t = 0 the key S1 is open The S2 key is closed 50 ms later. Determine:

a) v_C (t) to 0 ≤ t ≤ 0.05 s

b) v_C (t) to t ≥ 50 ms

Problem 22-5    Source:    Problem 7.30 - page 300    Book: Análise de Circuitos em Engenharia - J. David Irwin - 4ª edição - Ed. Pearson - 2013.

In the circuit shown in the Figure 22-05.1, the switch S remained open for a long time. In t = 0 the S key is closed. Determine the current i(t).