Astro Physics Question:

Magnetic effect of the earth. The earth behaves as it has
got a big magnet, running as mot a big magnet, running
almost from its north to south pole inside it (the earth).
Its south pole lies towards the geographical north pole and
the north pole lies towards the geographical south pole. As
a matted of fact, there is no such magnet inside it, but our
earth, as a whole, acts as a big magnet, we can prove this
fact with the help of the following experiments.

(1) one can magnetise iron
?rods by the earth. This is possible only when the earth
behaves like magnet or it has got magnetic material (a big
magnet) inside it.

(2)when we suspend a magnet.
Freely, it always rests in a particular direction almost
coinciding with the north and the south direction. It is
only possible when we presume that there is magnet inside
the earth of which north elope is towards soothe pole of
geography and south pole is towards geographical north pole.