Hello,

One reason behind earth's magnetic field is that Dynamo effect in magnetic effect is caused by the outer metallic fluids present on the earth. And the rotation of earth further causes the the whole magnetic field. This field is really very important as it protects earth from Solar radiation. Thank you and all the best

Hi.

Earth's magnetic field is caused by a dynamo effect.

On Earth , flowing of liquid metal in the outer core of the planet generates electric currents. The rotation of Earth on its axis causes these electric currents to form a magnetic field which extends around the planet.

I hope this answers your query.