You make a bandpass filter that has a bandwidth of 400 Hz If

You make a band-pass filter that has a bandwidth of 400 Hz. If your low end of the pass band is 100 Hz, which of the following sets of frequencies will be allowed to pass through?

a. 50, 200, and 400

b.200, 300, and 400

c. 200, 300, and 600

d. 50, 200, and 600

Solution

Low pass filter allows all frequencie below a specific value, termed as band edge frequency and block all high frequencies; where as high pass filter passes all high frequencies above certain band edge and block all low frequencies. The band pass filter blocks all frequencies betweeen these edges and allow the before and after edge frequencies.

Pass band frequencies are integral multiple of low edge frequency. In this case, the low edge frequency is 100 Hz.

Thus, the allowed frequencies are 200, 300, and 400 Hz

Correct option is ( b )