The earth has a magnetic field, as seen in the image above. the field lines defining the structure of the magnetic field are similar to those of a simple bar magnet. the axis of the magnetic field is tipped with respect to the rotation axis of the earth and true north, defined by the direction to the north rotational pole, does not coincide with magnetic north, defined by the direction to the north magnetic pole. the origin of the earth's magnetic field is not completely understood, but is thought to be associated with electrical currents produced by the coupling of convective effects and rotation in the spinning liquid metallic outer core of iron and nickel. this mechanism is termed the dynamo effect. rocks that are formed from the molten state contain indicators of the magnetic field at the time of their solidification. the study of such magnetic fossils indicates that the earth's magnetic field reverses every million years or so. one property of magnetic fields is that they exert forces on moving electrical charges. a magnetic field can trap charged particles such as electrons and protons and force them to move a spiraling motion back and forth along the field lines. high energy charged particles from the solar wind enter earth's magnetosphere and are the source of the charged particles trapped in the van allen belts. these belts coincide with the inner and outer field lines seen around earth. based on the information in the passage, check all the statements that are true. the earth's magnetic field reverses every million years or so. true north and the magnetic north pole are in the same exact location. the source of charged particles forming the van allen belts are mainly from the solar winds. the source of the earth's magnetic field may be found in the earth's core. no magnetic field exerts an influence on charged particles.