Problem + Hard 47-1    Font:    Problem 5.38 - page 120 -    NILSSON - RIEDEL -    Book: Electric Circuits - 8th edition - Ed. Pearson Education do Brasil - 2010.

Determine V₁ and V₂ in the circuit shown in the Figure 47-01.1 knowing that operational amplifiers are ideal.

Problem + Hard 47-2.    Source:   Exam Question for Electronic Engineer - Petrobras - 2012.

Resistive transducers are used in many industrial control systems. One way to measure the electrical resistance of a resistive transducer R_S is illustrated in the circuit shown in the Figure 47-02.1, where we consider the amplifiers ideal operations. Determine the value of electrical resistance R_S of the transducer through from a mathematical expression that is a function of the values ​​of the resistors that make up the circuit and the output voltage V_o.