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Passive Filters - Engineering

Q1:

A parallel resonant band-pass filter consists of a 90  resistor in series with a parallel network made up of a 60 mH coil and a 0.02 F capacitor. The output is taken across the capacitor/coil. The coil winding has a resistance of 20 . What is the center frequency of the filter?

A 459 Hz

B 4,591 Hz

C 999 Hz

D 2,176 Hz

ANS:B - 4,591 Hz

XL=Xc.

2*pi*f*L = 1/(2*pi*f*C).

f^2 = 1/(4*pi^2*L*C).
f^2 = 21129.99 hz.
f = sqrt (21129.99).
f = 4596.7 Hz.