Question

Notch is a ________

(a) High pass filter

(b) Low pass filter

(c) Band stop filter

(d) Band pass filter

This question was posed to me in a national level competition.

This intriguing question comes from Channel in chapter Elements of Communication System of Analog Communications

Answer 1

Right answer is (c) Band stop filter

To explain I would say: Notch filter is a band stop filter that allows most frequencies to pass through it, except frequencies in a specific range. It is just opposite of a band-pass filter. High pass filter allows higher frequencies to pass while Low pass filter allows lower frequencies to pass through it.