Electric field and current

[brood910]

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So, I know that electric field increases current.
However, I am kinda confused by the equations for resistivity + resistance..

Resistivity = Electric field/J
Resistance = resistivity x L/A


So, doesnt this mean increasing E will increase resistivity, which increases resistance as well?
If so, then since conductivity = 1/resistivity, conductivity will decrease, which decreases current as well.. Maybe I am not understanding resistivty = E/J fully. Can anyone clarify? Thanks

 

[SpaceBuff12]

It is important to understand the concept of J, current density, in the first equation. Current density is the current flux in the material, i.e. the current per unit area. If you increase the internal electric field but the current density does not change then the resistivity must increase.

Resistivity is an intrinsic material property (it can change with temperature, but for our purposes it is constant). Likewise, conductivity is an intrinsic material property as well (just the inverse of resistivity, as you noted).

You have the relationships down. Hopefully it is more intuitive now.