Problem 47-1    Source:  2ª question of 1º test - Electric Circuits - Ufrgs - 2017.

For the circuit shown in the Figura 47-01.1, calculate I_o in function of V_i.

Problem 47-2    Source:   Problem 5.74 - page 186 -    ALEXANDER, Charles K., SADIKU, Matthew N. O. -    Book: Fundamentos de Circuitos Elétricos - 5ª Edição - Ed. McGraw Hill - 2013.

Determine the current I in the circuit shown in the Figura 47-02.1.

Problem 47-3    Source:   Problem 5.62 - page 185 -    ALEXANDER, Charles K., SADIKU, Matthew N. O. -    Book: Fundamentos de Circuitos Elétricos - 5ª Edição - Ed. McGraw Hill - 2013.

Determine the voltage gain K = V_o / V_i, of the circuit shown in the Figura 47-03.1.

Problem 47-4    Source:   Problem 5.87 - page 187 -    ALEXANDER, Charles K., SADIKU, Matthew N. O. -    Book: Fundamentos de Circuitos Elétricos - 5ª Edição - Ed. McGraw Hill - 2013.

The circuit shown in the Figura 47-04.1 represents an instrumentation amplifier with two operational amplifiers. Deduct an expression for V_o in terms of V₁ and V₂. Explain how this   amplifier can be used as a subtractor.

Problem 47-5    Source:   Problem 5.79 - page 186 -    ALEXANDER, Charles K., SADIKU, Matthew N. O. -    Book: Fundamentos de Circuitos Elétricos - 5ª Edição - Ed. McGraw Hill - 2013.

In the circuit shown in the Figura 47-05.1, determine the value of V_o knowing the values of the input voltages, or V₁ = 5 V and V₂ = 1 V.

Problem 47-6    Source:   Problem 4.69 - page 218 - 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 shown in the Figura 47-06.1, determine the value of V_o in terms of V₁ and V₂.

Problem 47-7    Source:  Adapted from the 2nd question on the list of Elementary Electronics I - Ufrgs - 2019.

For the circuit shown in the figure below, determine the value of N so that the circuit has a predominance of negative feedback. Afterwards, consider the value of N so that the circuit presents a predominance of positive feedback.

Problem 47-8    Source:  Problem created by the site's authors.

For the circuit shown in Figure 47-8.1, considering V_i = 14.1 V, determine:

a) the value of the current I_x.

b) the voltage value V_o.

c) the voltage value V_m.

d) the value of the current I_o.