Engineering Board Exam Reviewer · Passive Filters · medium
A band-pass filter has half-power frequencies of 3 kHz and 12 kHz. Its center frequency, taken as the geometric mean, is
- 7.5 kHz
- 9 kHz
- 6 kHz
- 2.4 kHz
Answer
C. 6 kHz
Solution
f0=sqrt(f1f2)=sqrt((3000)(12000))=6000 Hz. (The arithmetic mean 7.5 kHz is not the center for a resonant filter.)
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