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 epsilon_(0))hat(n) + (Q_(2))/(2A epsilon_(0)) hat(n)`
`= (Q_(1) + Q_(2))/(2 A epsilon_(0))hat(n) = (Q)/(2A epsilon_(0)) hat(n)`
[This shows that the resultant field due to sheet depends only on the total charge of the sheet and not on the distribution of charge on individual surfaces].