Difficulty: Easy
Correct Answer: -6 dB per octave
Explanation:
Introduction / Context:Bode diagrams are frequency response plots showing system behavior on a logarithmic scale. The slope of the magnitude plot indicates how quickly the response falls with frequency. A single pole introduces a characteristic slope change.
Given Data / Assumptions:
Concept / Approach:
A single pole contributes –20 dB per decade beyond its corner frequency. Since one decade = 10× frequency and one octave = 2× frequency, the per-octave slope must be converted accordingly.
Step-by-Step Solution:
Slope = –20 dB per decade.1 decade ≈ 3.32 octaves (since log2(10) ≈ 3.32).Therefore slope per octave = –20 / 3.32 ≈ –6 dB per octave.Verification / Alternative check:
Textbook Bode plot rules confirm: each pole beyond the break frequency introduces a –20 dB/decade slope or equivalently –6 dB/octave.
Why Other Options Are Wrong:
Common Pitfalls:
Final Answer:
–6 dB per octave.
Discussion & Comments