Question

A signal containing both a 5k Hz and a 10k Hz component is passed through a low-pass filter with a cutoff frequency of 4k Hz. Which component(s) will be attenuated? g

Answer 1

Answer:

The 5 kHz signal will be less attenuated and the 10 kHz will be completely attenuated.

Low Pass Filter:

The purpose of a filter is to remove the undesired frequency components in a signal. A low-pass filter is one in which we allow low frequencies components to pass through it and block the higher frequency components. The frequency  where it starts to attenuate the signal is called cut-off frequency.

Explanation:

We have a signal that contains 5 kHz and 10 kHz frequency component.

The cut-off frequency is 4 kHz which means the filter will attenuate the frequency components of 4 kHz or greater than that.

So, in theory both 5 kHz and 10 kHz frequency components will be attenuated.

But filters are not ideal and they usually have a little margin also called roll off which means it will allow some of the frequency components greater than cut-off frequency of 4 kHz.

Conclusion:

So to conclude, the 5 kHz signal will be less attenuated and the 10 kHz will be completely attenuated.