Earth’s magnetic field behaves like a giant bar magnet with north and south poles. Many mechanisms have been postulated to explain how the magnetic field is generated, but the only one that is widely accepted is analogues to a dynamo. That is, Earth’s magnetic field is caused by a dynamo effect.
The mechanism is similar to that of the working of a dynamo start spinning when the bicycle is pedaled, creating an electric current. The electricity, thus created, keeps the light on. Magnetic fields occur whenever electric charge is in motion. If there is a rotating electric current, it will create a magnetic field.
The Earth’s magnetic field has its source in the flow of molten iron in its outer core. Electric current is generated due to the motion of convection currents of molten iron. The rotation of Earth on its axis causes these electric currents to form a magnetic field which extends around the planet.
Picture Credit : Google
