A Thin Conducting Plane with Surface Charge Density $\sigma$ Is Exposed to an External Electric E_ext

Multiple Choice

A thin conducting plane with surface charge density $\sigma$ is exposed to an external electric E_ext. The difference in the electric field between one surface of the plane to the other surface is

A) $\sigma$ / $\isin$ ₀
B) $\sigma$ / $\isin$ ₀ + E_ext
C) $\sigma$ / $\isin$ ₀ + E_ext.
D) 2 $\sigma$ / $\isin$ ₀ + E_ext
E) $\sigma$ /2 $\isin$ ₀ +E_ext.