# Illustration Electric Field Graph (inside / outside) - Hollow cylinder

Diagram of the electric field $$E(r)$$ of a charged hollow cylinder as a function of the distance $$r$$ from the longitudinal axis. The hollow cylinder has the radius $$R$$.
• Outside ($$r \gt R$$) of the hollow cylinder, the E-field is proportional to $$1/r$$.
• Inside ($$r \lt R$$), however, the hollow cylinder is field-free (Faraday cage).