Conductors
Ideal
- Electrons can freely move, i.e. \(\vec{F}=-e\vec{E}=0\)
- Hence, no electric fields in conductors, thus they form an equipotential.
- Additionally, the charge density inside a solid conductor must be zero.
- Charge accumulates on the surface of the conductor.
- Right above the surface, the electric field must be perpendicular to the surface, i.e. parallel to the surface normal.
- \(\vec{E}=\frac{\sigma}{\varepsilon_0}\hat{n}\) just above the field. Thus, we can get the charge density from the electric field just above the surface