Why is the Electric Field Constant Along a Charged Cylinder's Surface?

[Godwin Kessy]

Am really suprised when deriving electric field due to a uniform charged thin long rod! It was suprising to have a cylinder as a gausian surface!

actualy is that posible, that all along the surface of the cylinder has same field intensity and why?

also why are there no electric flux along the caps of the gausian surface "the cylinder"

 

[collinsmark]

Am really suprised when deriving electric field due to a uniform charged thin long rod! It was suprising to have a cylinder as a gausian surface!

actualy is that posible, that all along the surface of the cylinder has same field intensity and why?

also why are there no electric flux along the caps of the gausian surface "the cylinder"

Technically, Gauss' law only works for an infinitely long rod. If the rod is shorter than infinity, Gauss' law is just an approximation. But it makes a pretty good approximation if you are not dealing with anything close to the edge of the rod, and you are much closer to the rod than the rod is long.