Surface Current Density

#Physics
Current per unit width on a surface

$\displaystyle \vec{K}\equiv \frac{\mathrm{d}\vec{I} }{ \mathrm{d}l_{\perp}}$

• $\displaystyle \mathrm{d}\vec{I}$ is the current on a surface
• $\displaystyle \mathrm{d}l_{\perp }$ corresponds to the length of wire perpendicular to the current
  

$\displaystyle \vec{K}=\sigma \vec{v}$

• $\displaystyle \sigma$ is the surface charge density
• $\displaystyle \vec{v}$ is the velocity of the charge density