The output impedance of a non-ideal operational amplifier is denoted by \( Z_{out} \). The variation in the magnitude of \( Z_{out} \) with increasing frequency, \( f \), in the circuit shown below, is best represented by:
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For non-ideal operational amplifiers, output impedance often exhibits a step-like change with frequency, which is commonly represented in a log-log graph.
Step 1: Understanding operational amplifier behavior.
The output impedance of an operational amplifier varies with frequency. As the frequency increases, the impedance often changes with a characteristic pattern, such as a step response or gradual decrease. For non-ideal amplifiers, this behavior is typically represented on a log-log scale.
Step 2: Analyzing the options.
- (A) \( \log(|Z_{out}|) \) vs \( \log(f) \): This is not the correct behavior for a non-ideal operational amplifier.
- (B) \( \log(|Z_{out}|) \) vs \( \log(f) \) (linear): This is not typical for the behavior of \( Z_{out} \) in an operational amplifier.
- (C) \( \log(|Z_{out}|) \) vs \( \log(f) \) (step response): This is the correct behavior, as the impedance often changes in a step-like manner with increasing frequency.
- (D) \( \log(|Z_{out}|) \) vs \( \log(f) \) (decreasing): This is not representative of the typical variation of output impedance with frequency in non-ideal operational amplifiers. Step 3: Conclusion.
The correct answer is (C), as the impedance of the operational amplifier typically varies with frequency in a step-like fashion in the given scenario.
