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Wed 24 Jan, 2018 11:31 am
earth has a magnet with two poles.but why it still did'nt get demagnetised though extremely hot lava/magma is present?
The magnetic core of the Earth is not a permanent magnet, like a bar magnet made of iron (which could be demagnetised by heat, impact etc). It is a "geodynamo", that is a form of electrical generator composed of the rotating molten iron alloys at the earth's core. Incidentally, this is why the field changes over time.