When a low-pass and a high-pass filter are cascaded to get a band-pass filter, the critical frequency of the low-pass filter must be

To determine the critical frequency of the low-pass filter in a cascaded low-pass and high-pass filter configuration, we need to follow these steps:

1. Understand the concept of a low-pass filter: A low-pass filter allows frequencies below a certain cutoff frequency to pass through while attenuating frequencies above that cutoff.

2. Understand the concept of a high-pass filter: A high-pass filter allows frequencies above a certain cutoff frequency to pass through while attenuating frequencies below that cutoff.

3. Recognize that a band-pass filter is created by cascading a low-pass and a high-pass filter: Cascading means connecting the output of one filter to the input of another.

4. Determine the desired band-pass filter's frequency range: This will help us determine the appropriate cutoff frequencies for the low-pass and high-pass filters.

5. Calculate the critical frequency for the low-pass filter: The critical frequency is the cutoff frequency at which the low-pass filter starts attenuating frequencies. It should be set below the desired band-pass filter's lower cutoff frequency.

6. Set the critical frequency for the low-pass filter: Based on the desired band-pass filter's frequency range, set the critical frequency of the low-pass filter accordingly.

By following these steps, we can determine the critical frequency of the low-pass filter in a cascaded low-pass and high-pass filter configuration to achieve a band-pass filter.