In two-pole low-pass, What is the roll-off rate at frequencies outside the passband?
a) -80 db/dec
b) cannot be determined
c) -40 db/dec
d) -60 db/dec
d) -60 db/dec
In a two-pole low-pass filter, the roll-off rate at frequencies outside the passband can be determined based on the filter's order.
The order of a low-pass filter refers to the number of poles it has. Each pole adds a roll-off rate of -20 dB/decade to the overall roll-off rate.
Since a two-pole low-pass filter has two poles, each contributing -20 dB/decade, the total roll-off rate at frequencies outside the passband is -40 dB/decade.
Therefore, the correct answer is c) -40 dB/dec.