# Fundamental Physics/Electromagnetism/Electromagnetization

Electromagnetization is defined as the way a coil of N circular loops turn metal inside the loops into a electromagnet

When the coil conducts current, Magetic field is created

${\displaystyle B=LI={\frac {N\mu }{l}}I}$

This magnetic field generates Magnetic field in metal

${\displaystyle H={\frac {B}{\mu }}={\frac {NI}{l}}}$

This phenomenon can be express by 4 Maxwell's vector differential equation below

${\displaystyle \nabla \cdot D=\rho }$
${\displaystyle \nabla \times E=-\nabla B}$
${\displaystyle \nabla \cdot B=0}$
${\displaystyle \nabla \times H=J+\nabla B}$