Problem 23-1    Source:   Problem elaborated by the author of the site.

In the circuit show in the Figure 23-01.1, the S switch has been closed for a long time. For the time t = 0   the switch has been opened. Calculate:

a) the current i to t ≥ 0.

b) the voltage v to t ≥ 0.

Problem 23-2   Source:    Problem 7.35 - page 301    Book: Análise de Circuitos em Engenharia - J. David Irwin - 4ª edição - Ed. Pearson - 2013.

In the circuit show in the Figure 23-02.1, the S switch has been closed for a long time. For the time t = 0   the switch has been opened. Calculate the current i(t) to t ≥ 0.

Problem 23-3    Source:    Problem 7.39 - page 302    Book: Análise de Circuitos em Engenharia - J. David Irwin - 4ª edição - Ed. Pearson - 2013.

In the circuit show in the Figure 23-03.1, the S switch has been closed for a long time. At t = 0   the switch has been opened. Find V_o (t) to t > 0.

Problem 23-4    Source:   Exercise 7-15 - page 329 -    THOMAS, Roland E. , ROSA, Albert J. , THOUSSAINT, Gregory J. -   Book: The Analysis & Design of Linear Circuits - 6ª Edição - Ed. John Willey & Sons, Inc. - 2009.

In the circuit show in the Figure 23-04.1, the S switch has been closed for a long time in position a. In t = 0   the switch has moved to position b.

Calculate the voltage v(t) to t > 0.

Problem 23-5    Source:   Exercise 7.13 - page 158 -    NILSSON, James W. & RIEDEL, Susan A. - Book: Circuitos Elétricos - Ed. LTC - 5ª edição - 1999.

In the circuit show in the Figure 23-05.1, the S₁ switch remained open for a long time, while the key S₂ remained closed for a long time. The S₁ switch is closed when t = 0 and, after remaining closed for 1 s, it is opened again. The S₂ switch is open when t = 1 s. Determine expressions for current i in the inductor that are valid in the ranges:

a) 0 ≤ t ≤ 1.

b) t ≥ 1.

Attention - In the problem statement there is a typo error in the letter b. Where it says t ≤ 1 s read on t ≥ 1 s.

Problem 23-6    Source:   Problem 3.5 - page 11 -     Prof. Dr. João Costa Freire - Instituto Superior Técnico - Portugal     Book: Analysis of Circuits - 2006. Available at: http://web.ist.utl.pt/pedro.m.s.oliveira/ProbAC.pdf

Determine the expression for i_L in the circuit shown in the Figure 23-06.1.

Problem 23-7    Source:   Problem 3.9 - page 11 -     Prof. Dr. João Costa Freire - Instituto Superior Técnico - Portugal     Book: Analysis of Circuits - 2006. Available at: http://web.ist.utl.pt/pedro.m.s.oliveira/ProbAC.pdf

Determine the expression for V_o in the circuit shown in Figure 23-07.1, when key S is in position 2, knowing that it has been in position 1 for a long time.