Minimum pieces for a checkmate

Analyze a position where black is left with a king only.
 Now, what is the minimum number of pieces (depending upon blacks king's position ) required for white to checkmate black .
   It will be great if you can give position of white pieces also.

A king and a queen or rook can give checkmate vs a lone king so 2.

If with minor pieces at least two but only if it's the Bishop pair or a Bishop and Knight. Two Knights alone can't force a mate unless their is a pawn or two involved. With heavy pieces then one should be enough such as a solo Rook and King vs solo King or even King and Queen vs solo King.

Actually I have checkmated the computer once with a solo Bishop and pawn. So their are rare instances where it's possible to mate with a solo minor pieces such as a knight if the opposing King is smothered by one of his pieces or pawn etc.

King and pawn vs king and pawn also possible (but before that there must be another piece on the board).

Strangemover is correct: the minimum number of pieces required to checkmate a lone king is two; one king and one queen or rook.

DeirdreSkye is also correct. The minimum strength required to force checkmate against a lone king is a king and two minor pieces.

A knight alone can sometimes perform a smothered mate against an enemy king if the enemy king is surrounded by friendly pieces.

2 pawns no promote

pretty sure it's 2

Wow. You are right. I missed those words earlier.

Not sure if a king and a passed pawn versus a lone king will suffice to the above question, even though the pawn has to be first promoted to a queen or rook safely,

Assuming there are no pawns an your opponent only has their king left then a rook would be the minimium required to get a checkmate.

@ShaoniHiya

Four times you posted above. Therefore, four times your conclusion is inaccurate.

Thank you for supporting me Eric! Yeah, he said when there is a lone king. The second the Q was sacrificed, it became lone king v. King and 2 pawns. But this is like fools mate, possibly even worse: HOW COULD YOU BLUNDER LIKE THAT A QUEEN UP!? And then get mated faster.

Wouldn't king and two minor pieces normally be regarded as stronger than king and rook in a basic endgame, at least if the two minor pieces are not both knights? 

It's difficult to ascertain if king and two minor pieces would be stronger than king and rook in an endgame involving all the relevant pieces, especially if there are no pawns left (i.e. KBN vs KR is going to be quite uncertain). But the sheer trickiness of the knight is what makes it appear difficult for the side having the rook to hold on, since the number of pitfalls is plenty

But from the simplest case of checkmating, KR vs K is easier than KBN vs K.