1. The problem statement, all variables and given/known data Assume two perpendicular planes one with charge density [itex]\sigma[/itex] and the other with a charge density [itex]2\sigma[/itex]. Find the electric field. //| //| //| //| [itex]\sigma[/itex] | //| _ |__________________ //|////// [itex]2\sigma[/itex]/////////////// //| 2. Relevant equations 3. The attempt at a solution I got a question. Can I assume that the planes are infinitly long, specially close to the origin? In such a case, I could apply the Gaus-law.