If an isollated infinite sheet contains charge `Q_(1)` on its one surface and charge `Q_(2)` on its other surface, then prove that electric field intensity at a point in front of sheet will be `Q/(2A epsi_(0))`, where `Q=Q_(1)+Q_(2)`

Explanation

Electric field at point P :
`vec(E)=vec(E)_(Q_(1))+vec(E)_(Q_(2))=Q_(1)/(2A epsi_(0)) hat(n)+Q_(2)/(2Aepsi_(0)) hat(n)=(Q_(1)+Q_(2))/(2Aepsi_(0)) hat(n)=Q/(2A epsi_(0)) hat(n)`
[This shows that the resultant field due to a sheet depends only on the total charge of the sheet and not on the distribution of charge on individual surfaces].