Question

In a certain parallel resonant band-pass filter, the resonant frequency is 14 kHz. If the bandwidth is 4 kHz, the lower frequency is

• A. 6 kHz
• B. 16 kHz
• C. 12 kHz
• D. Cannot be determined

Answer 1

Answer: (C)

12 kHz

Given that resonance frequency is $14kHz$ and the bandwidth is $4kHz$

We know that bandwidth is equal to twice the frequency of signal

$\Rightarrow B=2\times f$

$\Rightarrow 4=2\times f$

So the signal frequency $f=\frac{4}{2}=2$

Therefore the higher frequency is $14+2=16kHz$ and the lower frequency is $14-2=12kHz$

Therefore option $C$ is correct