What tuning is Iron Man played in?
It is in standard tuning, the key is B and it is minor. You can kind of get away with playing the original in other tunings, because there are virtually no open strings in the song, but you might make the few times they do pop up more difficult in the long run.
What is AB power chord?
B – F# (Gb) Power Chords are diatonic chords without third interval notes, used often in heavy metal, and generally whenever you play under heavy distortion. Since power chords have no thirds, they are neither major nor minor.