E = σ/2εnot, this equation is used for finte sheet of charge. Can we use the same result for finite sheet of charge ? If yes give reasons, if no suggest the changes in the equation.

Question

anonymous · Answer

No, you cannot use the same result.
If you have an infinite charage distribution, it does not matter how far you are away, it will always appear as a huge infinite plane.
If you have however a finite sheet, if you are just far enough away, the sheet will look like a point  charge. Therefore it will follow the 1/r^2 law instead of being constant as for the infinite sheet

anonymous · Answer

No you can't because of the fringe field