GEOLOGY

Detailed explanation-1: -When we join the points, we get a pattern of lines which emerge from the north pole and enter at the south pole. Inside the magnet, the magnetic field lies go from south pole to the north pole. Hence, they form closed loops.

Detailed explanation-2: -Magnetic field lines outside of a permanent magnet always run from the north magnetic pole to the south magnetic pole. Therefore, the magnetic field lines of the earth run from the southern geographic hemisphere towards the northern geographic hemisphere.

Detailed explanation-3: -The direction of the magnetic field is taken to be the direction in which a north pole of the compass needle moves inside it. Therefore it is taken by convention that the field lines emerge from north pole and merge at the south pole.

Detailed explanation-4: -Magnetic field lines are the imaginary lines around a magnet which gives us the pattern of magnetic field of the magnet. These lines don’t start or end. They form a closed loop. They flow from North pole to South pole outside the magnet, while they flow from South pole to North pole inside the magnet.