Engineering Board Exam Reviewer · Passive Filters · medium
A second-order passive low-pass filter (two reactive sections) rolls off at what rate beyond its cutoff frequency?
- 20 dB per decade
- 40 dB per decade
- 60 dB per decade
- 3 dB per decade
Answer
B. 40 dB per decade
Solution
Each reactive section adds 20 dB per decade of attenuation, so two sections give 40 dB per decade (12 dB per octave).
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