Problem 45-1    Source:  Problem 4-29 - page 212 -   THOMAS, Roland E. , ROSA, Albert J. , THOUSSAINT, Gregory J. -    Book: The Analysis & Design of Linear Circuits - 6ª Edição - Ed. John Willey & Sons, Inc. - 2009.

Suppose that in circuit show in Figure 45-01.1, S key is initially open.

a) Find V_o in terms of V₁ and V₂.

b) Repeat the calculation for the closed S key.

Problem 45-2    Source:  Problem 4-34 - page 213 -    THOMAS, Roland E. , ROSA, Albert J. , THOUSSAINT, Gregory J. -   Book: The Analysis & Design of Linear Circuits - 6ª Edição - Ed. John Willey & Sons, Inc. - 2009.

Use the nodal analysis method to show that in the circuit of the Figure 45-02.1 i_o = - V_s / 2 R , independent of the load R_L. In other words, show that the circuit of the figure below is a current source voltage controlled (V_s).

Problem 45-3    Source:    Problem 5.39 - page 120 -    NILSSON & RIEDEL -    Book: Circuitos Elétricos - 8ª edição - Ed. Pearson Education do Brasil - 2010.

In the circuit show in Figure 45-03.1, the resistor R_x is set so that the ideal operational amplifier is exactly at the point of saturation. Determine the value of R_x in kΩ.