This was a question that came in a exam. How come is this possible?
Actually, a question on the source of Earth's magnetic field was asked here on physics SE, which matches my opinion.
The source of Earth's magnetic field is the molten iron and metals in the earth's core. The spinning of these liquid metals produces the same effect as electric current in a coil which produces a magnetic field.
Yes, that is true. Circulating ions of iron and nickel in a highly conducting liquid of Earth's core forms current loops and produces a magnetic field.
There is something to do with geologist though I'm not getting it. How come geologist doesn't seem to agree with this?
Best Answer
Italics mine.
The liquid iron, as the other answer states , cannot have a permanent field.
There may be a mechanism by which the solid core may have a weak magnetic field. An initial magnetic field is needed for the dynamo model to work:
......
The dynamo model is still a subject of research.
Maybe you have misunderstood the question, or it was badly stated in the exam. Maybe the stress was on permanent magnetism?