Kings cant be on a1 and b2 simultaneously
kings after a capture

If that was the case, then this wouldn't be checkmate.
Not to mention, the position you've described is illegal. And if it was legal, why would you not take the king instead?
~~~there is a black king is on a1 and white king is on b2~~~
As stated, this position is illegal. Two Kings can never be touching each other.
~~~there is a black king is on a1~~~/~~~~and a black queen is on b1, if the black king kills the queen ~~~~~
Two things you said, an illegal position to begin with, but again illegal because a piece never captures its own piece Black does not capture black, and white does not capture white.
However, any time there are only 2 kings and one piece (any piece) and that piece is legally captured, then yes, it is a drawn game.
there is a black king is on a1 and white king is on b2 and a black queen is on b1. if the black king kills the queen does it mean it a draw as there is only kings.