If the earth is itself a magnet, can you guess the poles of earth's magnet by looking at the direction of the magnetic compass?
Yes, the poles of Earth's magnet can be identified by observing the magnetic compass.
The North pole of a compass needle points towards the geographic North of Earth. Since magnetic poles follow the rule that unlike poles attract each other, the geographic North pole of Earth must have a magnetic South pole.
Similarly, the geographic South pole of Earth must have a magnetic North pole.
Therefore, Earth behaves like a giant magnet with its magnetic South pole near the geographic North and its magnetic North pole near the geographic South.
Explanation
The chapter states that 'A freely suspended magnet rests along the north-south direction because our Earth itself behaves like a giant magnet.' Since the North pole of the compass needle is attracted towards the geographic North, and unlike poles attract each other, the Earth's magnetic South pole must be located near the geographic North pole. This is why the compass needle's North pole points northward.
Solution Steps
The North pole of a compass needle points towards the geographic North of Earth.
Since unlike poles attract each other, the geographic North pole of Earth must have a magnetic South pole.
Similarly, the geographic South pole of Earth must have a magnetic North pole.
Earth behaves like a giant magnet with its magnetic South pole near the geographic North.