Can you solve the MAGNET RIDDLE? ft YouTube CEO Susan Wojcicki

Answer to magnetic riddle:
Use rope to hang one bar up from the ceiling. Put the other bar below it (not touching) and let them settle.
Then try rotating the bottom bar. If the hanging bar is magnetic its movement will affect the hanging bar and it should start turning as well.

If magnetic bar is the hanging one, then it will align across earth's magnetic line acting as a Compass, and so rotating normal bar will not affect its orientation.