About this ebook
A central theme of this chapter is the study of Earth’s magnetism. The planet acts as a giant magnetic dipole, surrounded by a field that shields us from solar radiation. This field is characterized by three parameters: magnetic declination, magnetic inclination (or dip), and the horizontal component of Earth's magnetic field, which altogether help in navigation.
Furthermore, the chapter classifies all materials into three primary categories based on how they respond to an external magnetic field:
Diamagnetic materials: Weakly magnetized in a direction opposite to the applied field (e.g., bismuth, copper).
Paramagnetic materials: Weakly magnetized in the direction of the applied field (e.g., aluminum, oxygen).
Ferromagnetic materials: Strongly magnetized in the direction of the field, capable of becoming permanent magnets (e.g., iron, nickel).
Understanding these properties is crucial for designing everything from simple magnetic compasses to advanced data storage devices and electromagnets.
