1. The problem statement, all variables and given/known data A rod with charge linear density λ is located at the long axis of a cylinder with charge linear density 2λ. With this information use Gauss's law to find (a) the charge linear density on the interior and exterior surfaces of the cylinder (b) the electric field outside of the cylinder at a distance r from the rod. Just to make sure: my questionnaire does refer to charge linear density, not surface density. My questionnaire does not make reference to a "long" rod nor a "long" cylinder. I've read these calculations are next to impossible if there's no reference to "longness". 2. Relevant equations Θ=q/ε q=λL -- for the rod 3. The attempt at a solution This question does not make any sense to me. So I'm not going to try to answer it, because I'm in disagreement with the question. I hope you also consider the question is wrong or weird or prove me wrong so I can understand. Thanks a lot.