How to approach these kind of questions sir

How to do this question sir.

sir,can we solve this question by the unbalanced wheatstone bridge technique you told us?..i tried to solve it by that trick but it becomes very complicated...

sir,why the answer of resistance is finite? sir,please clear this concept.

sir solution me H"=i*2*10 nhi hona chahiye instead of 4?kyuki current to 6 and 4 dono resistances se flow hoga?