How to Calculate the E Field Inside a Charged Cylinder?

[cragar]

This is not a homework problem. Let's say I have an infinite charged cylinder with radius R .
And I want to find the E field inside the cylinder. If the cylinder has a line charge of T, that is charge per length. would the charge enclosed just be the ration of the areas of the smaller radius to the larger fixed radius of the cylinder.
would Q equal $\frac{Tr^2}{R^2}$

 

[mfb]

??
As you have a "smaller radius" and a "larger radius", I think you mean a hollow cylinder, similar to this?
To find the electric field inside, you can use the symmetry of the problem and Gauss's law, you do not need any total charge to do that.

Which charge, where?