Electric field in a more difficult situation

[umciukas]

Could someone give me any ideas on how to calculate the electric field betweet two different size charged plates? The situation sounds like this: a neutral conducting plate is put near a charged smaller plate.
Could I say that the induced charge on the bigger plate is uniformly distributed? Otherwise how could I estimate the exact charge distribution?

 

[Curl]

Can't say it is evenly distributed. The calculation is not trivial. Even for identical plates the calculations are difficult so expression you often see is actually an approximation for large plates (high area/perimeter ratio).