Electrical Circuit Worksheet [Thevenin, Norton, op-amp, step-response]

Problem 1 (20 pts): Assume the two op amps are ideal.

(a) Write an equation for the output voltage, vo, in terms of the input voltage, vi, and the three resistors R1, R2, and R3. [5 points]

(b) Select resistors R1, R2, and R3 such that |vo| = 100|vi|. [5 points]

(c) Suppose both op amps have ±25 V supply voltages and the resistors satisfy part (b). What is the maximum input voltage for which this amplifier remains in the linear region (i.e., the op amps do not saturate)? [5 points]

(d) What sort of amplifier is this (inverting, noninverting, neither)? [5 points]

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Problem 2 (30 pts): Consider the following circuit. Find both the Thévenin and Norton equivalent with respect to terminals a and b. Be sure to label which is which.

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Problem 3 (30 pts): The switch in the circuit below has been closed for a long time before it opens at time t = 0.

(a) Find v(t) for t > 0. [15 points]

(b) Find i(t) for t > 0. [15 points]

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Problem 4 (20 pts): In the circuit below, the switch has been closed for a very long time before it opens at time t = 0. Find the voltage v(t) for t ≥ 0. You may assume an ideal op amp with ±20 V supplies.

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