Poynting Vector

Topics

• Electromagnetic Energy

$\vec{S}=\frac{1}{{\mu }_0}(\vec{E}\times \vec{B})$

• Points toward the direction of energy flow (e.g. in the case of light)
• ${\mu }_0$ is the magnetic constant
• $\vec{E}$ is the electric field
• $\vec{B}$ is the magnetic field

$\vec{S}=\frac{1}{\mu }(\vec{E}\times \vec{B})$

• In the case when EM waves travel through materials
• $\mu$ is the permeability of the material