12.1 Magnetic Fields

Magnetic Fields

A magnetic field is a vector field that surrounds magnets and moving electric charges. It exerts a force on other magnetic materials and moving charges within the field. Magnetic fields are created due to magnetic dipoles in atoms or due to movements of charged objects. Magnetic fields are represented using field lines that flow from the north pole to the south pole in a closed loop outside a magnet. Magnetic fields are designated with the variable B and have units of Teslas (T).

A magnetic being as powerful as a single tesla is fairly uncommon. For context a house magnet has a magnetic field strength of around ${10^{-8} T}$ and the strongest magnet in the world can produce a field of 45 Tesla (this is enough to levitate non-magnetic objects). For this reason magnetic fields are often measured using the unit Gauss (G) which is equal to ${10^{-4} T}$.