Key Equations

Displacement current	$I_{d} = ε_{0} \frac{d Φ_{E}}{d t}$
Gauss’s law	$\oint \vec{E} \cdot d \vec{A} = \frac{Q_{in}}{ε_{0}}$
Gauss’s law for magnetism	$\oint \vec{B} \cdot d \vec{A} = 0$
Faraday’s law	$\oint \vec{E} \cdot d \vec{l} = - \frac{d Φ_{m}}{d t}$
Ampère-Maxwell law	$\oint \vec{B} \cdot d \vec{l} = μ_{0} I + ε_{0} μ_{0} \frac{d Φ_{E}}{d t}$
Wave equation for plane EM wave	$\frac{\partial^{2} E_{y}}{\partial x^{2}} = ε_{0} μ_{0} \frac{\partial^{2} E_{y}}{\partial t^{2}}$
Speed of EM waves	$c = \frac{1}{\sqrt{ε_{0} μ_{0}}}$
Ratio of E field to B field in electromagnetic wave	$c = \frac{E}{B}$
Energy flux (Poynting) vector	$\vec{S} = \frac{1}{μ_{0}} \vec{E} \times \vec{B}$
Average intensity of an electromagnetic wave	$I = S_{avg} = \frac{c ε_{0} E_{0}^{2}}{2} = \frac{c B_{0}^{2}}{2 μ_{0}} = \frac{E_{0} B_{0}}{2 μ_{0}}$
Radiation pressure	$p = {\begin{matrix} I / c & Perfect absorber \\ 2 I / c & Perfect reflector \end{matrix}$