Formula: Wave Equation for B-Field
$$\nabla^2 \, \class{violet}{\boldsymbol{B}} ~=~ \mu_0 \, \varepsilon_0 \, \frac{\partial^2 \class{violet}{\boldsymbol{B}}}{\partial t^2}$$
Magnetic field
$$ \class{violet}{\boldsymbol{B}} $$ Unit $$ \mathrm{T} $$
Solving the vectorial wave equation with the respective boundary conditions yields the magnetic field. For example, a simple solution of the wave equation yields the B-field in the form of plane waves.
Vacuum Permittivity
$$ \varepsilon_0 $$ Unit $$ \frac{\mathrm{As}}{\mathrm{Vm}} $$
The vacuum permittivity is a physical constant that appears in equations involving electromagnetic fields. It has the following experimentally determined value:
$$ \varepsilon_0 ~\approx~ 8.854 \, 187 \, 8128 ~\cdot~ 10^{-12} \, \frac{\mathrm{As}}{\mathrm{Vm}} $$
Magnetic field constant
$$ \mu_0 $$ Unit $$ \frac{\mathrm{Vs}}{\mathrm{Am}} $$
It is a natural constant and occurs whenever electromagnetic fields are involved. It has the value \( \mu_0 = 4\pi \cdot 10^{-7} \, \frac{ \text{N} }{ \text{A}^2 } \).
Nabla operator
$$ \nabla $$ Unit $$ \frac{1}{\mathrm m} $$
The operator \(\nabla^2\) is applied to the magnetic field to differentiate the components of the B-field according to the spatial coordinates \(x,y,z\).
Applying \(\nabla^2\) to the B-field yields a vector quantity. The first component of this vector quantity is: \[ \frac{\partial^2 B_x}{\partial x^2} + \frac{\partial^2 B_x}{\partial y^2} + \frac{\partial^2 B_x}{\partial z^2} ~=~ \mu_0 \, \varepsilon_0 \, \frac{\partial^2 B_x}{\partial t^2} \]