When making AM radio, I know that Band pass filter is necessary. As you know, there's 2 ways to make R L C Band pass filter, one is parallel R with parallel LC and the other is series R L C. But almost every AM radio circuit I saw uses R with parallel LC. Is there any special reasons?
Here are some things to look at when looking for differences between these circuits:
What is the input impedance of the filter, in both the pass-band and the stop-bands?
What is the output impedance of the filter, in both the pass-band and the stop-bands?
Let me confuse you more...
Would you say the following circuit is series-resonant or parallel resonant?
It is certainly resonant at 455 kHz., and delivers power from the generator to the detector load (R2).
You'll find that many LC circuits used in AM radios have tapped coils, or coils having different number of turns mutually linked, so that source impedances and load impedances can by matched. Yes, most of their inductance resonates with a parallel capacitor, but it is limiting to say strictly "it is a parallel resonant circuit", especially where greatly-differing impedances are involved.