What parameter is decreased when feedback is applied __________?
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Answer: B. system gain
Explanation
Negative feedback divides the open-loop gain by a factor incorporating loop gain magnitude. This mathematical reduction stabilizes amplifier performance against component parameter variations. Consequently, applying feedback reliably decreases the overall system gain magnitude. Closed-loop gain is expressed as forward gain divided by one plus the loop gain product. While gain is reduced, feedback simultaneously increases system bandwidth and linearity. Harold Black invented negative feedback amplifiers to overcome distortion in telephone systems.
Operational amplifier circuits use feedback resistors to set precise, stable closed-loop gains. Audio amplifiers sacrifice raw open-loop gain to achieve crystal-clear, distortion-free sound reproduction. Reducing gain is a necessary trade-off for improving overall system robustness and stability. System stability is typically improved or maintained rather than decreased by negative feedback. Option C is incorrect because stability is not decreased when applying negative feedback. Option D is wrong since system gain is definitively decreased by feedback loops.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
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