What is the importance in saying that magnetic field lines runs from north to south pole?
why did we even consider the emergence of the field line from one of the poles? What is the reason we did not consider the generation of those lines with help of both the poles?
It is not that the field lines are generated from one of the poles. The field lines are generated due to Molten metal ions rotating in the core of Earth generating the magnetic field. The magnetic field lines are due to this magnetic field only and the emerge not exactly at the geograpical north pole, they emerge from the magnetic north pole which is different.