Identify the magnetic north pole of earth's magnet

As we know that magnetic field lines always originated out from the north pole of magnet and then terminate at south pole of the magnet

So here in order to find out the magnetic north pole we can say that magnetic field lines will originated out from that pole

In order to find out that part of earth from which magnetic field lines originated out we have to suspend a bar magnet freely in the air.

Now the south pole of bar magnet is always attracted towards the North pole of Earth magnetic field

So when We freely suspend the bar magnet then its south pole always shows the position of North pole of Earth magnetic field.

So we can say that the Geographic south position of Earth is the magnetic North pole of Earth

electromagnetic shielding is the practice of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive or magnetic materials. shielding is typically applied to enclosures to isolate electrical devices from their surroundings, and to cables to isolate wires from the environment through which the cable runs. electromagnetic shielding that blocks radio frequency electromagnetic radiation is also known as rf shielding.

the shielding can reduce the coupling of radio waves, electromagnetic fields and electrostatic fields. a conductive enclosure used to block electrostatic fields is also known as a faraday cage. the amount of reduction depends very much upon the material used, its thickness, the size of the shielded volume and the frequency of the fields of interest and the size, shape and orientation of apertures in a shield to an incident electromagnetic

from wikipedia