In the first order low pass filter, which one of the following statements is not correct ?

Question

Question

This question was previously asked in

ESE Electrical 2021 Official Paper

It has the maximum gain at frequency of 0 Hz.
At higher cutoff frequency, the gain falls to 0.707 times the maximum gain.
For frequency greater than higher cutoff frequency, the gain decreases at a constant rate of -20 dB/decade.
It has the maximum gain in stop band.

Answer 1

The gain to frequency plot of a low pass filter is shown below:

F1 Koda 16-12-21 Savita D2

With reference to frequency response of first order low frequency response:

At f = 0, gain = A which is the maximum gain. Thus it has maximum gain at frequency of 0 Hz.
The higher cutoff frequency occurs at 0.707 (1/\( \sqrt{2}\)) times the maximum gain.
For frequency greater than higher cutoff frequency, the gain decreases at a constant rate of -20 dB/decade.