# transfer function pols

i am third year Electrical engineering student, i have some issues that i could not find a good explanation for it. lets say we have an RC circuit (low pass configuration). if we calculate the transfer function we get Vo/vi=1/1+RCS. so we have a single pole in s=-1/RC. my question is what will happened to transfer function we stimulate the system in frequency that is equal to the system pole. i would expect it to blow since the denominator is zero in this case, but if we look at the frequency of this system it never blow. so what am i missing here? is it possible at all to stimulate the system in it pole frequency? thanks!

• And s-domain is just a mathematical abstraction that helps us in this case (we do not need to solve a differential equation). And s-domain does not exist in reality. And in s-domain complex plane approaches infinity at the pole frequency but, such a situation is not possible in reality. In reality, we have a corner frequency at this point (-3dB for a first-order circuit). So to get a real response set s=jw into the transfer function and take the magnitude.
– G36
Apr 18, 2020 at 20:15
• ok thanks,can you please say more why this situation is nit possible in reality? Apr 18, 2020 at 20:47
• Eli, check Andy's answer here: electronics.stackexchange.com/a/316924/43172
– Mike
Apr 18, 2020 at 22:44