### An electric field of two positively charged parallel plates:

Two thin plane-parallel sheets of charge having uniform charge densities

**σ1****and****σ1****with****σ1>σ2>0**Suppose**r^****is a unit vector pointing from left to right.**Field due to the two sheets |

**In region (I):**Field due to the two sheets are

**E1−→=−σ12ϵ0r^...and..E2−→=−σ22ϵ0r^**

from the principle of superposition the total electric field at any point of the region, I is

**EI−→=E1−→+E2−→=−r^σ1+σ22ϵ0**

**In Region (II):**Field due to the two sheets are

**E1−→=σ12ϵ0r^...and...E2−→=−σ22ϵ0r^**

**EII−→−=E1−→+E2−→=r^σ1−σ22ϵ0**

**In Region (III):**

**Field due to the two sheets are**

**E1−→=σ12ϵ0r^...and...E2−→=σ22ϵ0r^**

**EIII−→−=E1−→+E2−→=r^σ1+σ22ϵ0**

**σ**