Magnetic Field of the Earth
A bar magnet or a compass when hanged from their gravitational center, they come equilibrium at north-south pole direction of the earth. This situation shows that there must be magnetic field acting on compass and bar magnet. This magnetic field is the earth’s magnetic field. The reason for this magnetic field is not explained yet however, most of the scientists believe that, earth’s magnetic field looks like magnetic field of a bar magnet. Picture given below shows the magnetic field lines of the earth; The geographic poles and magnetic poles do not coincide actually. There is a 11o angle between the geographic poles and magnetic poles. We call magnetic declination this deviation. Picture given below shows the geographic poles and magnetic poles of earth.