Question

you have been given a bar magnet and asked to mark its north and south poles how would you do that?

Answer 1

We tie a thin and strong thread  to the center of the bar magnet and then hang that vertically from a height.  It rotates freely in horizontal and the south pole of the magnetic will point to the North pole of Earth.

North Pole of Magnet will point towards South pole of Earth.

Answer 2

firstly take another bar magnet which marked as north to south and then joint the magnet north to one side if it atrract then that is the south area if its repel then that is the north area.....
I think it helpss you