Electric field intensity at a point near an infinitely charged plane sheet having surface charge density
`oint vecE.vec(dA) = int_text(front surface) vecE.vec(dA)`
` + int_text(curved surface) vecE.vec(dA)`
` + int_text(rear surface) vecE.vec(dA)`
`= int_text(front surface) E.(dA) cos0^o`
` + int_text(curved surface) E.(dA) cos90^o`
` + int_text(rear surface) E.(dA) cos0^0`
`= int E dA + 0 + int E dA`
`= 2EA`
From gauss law
`oint vecE.vec(dS) =sum q_(en)/epsilon_0 = (sigmaS) /epsilon_0`
`E = sigma/(2epsilon_0)`
` + int_text(curved surface) vecE.vec(dA)`
` + int_text(rear surface) vecE.vec(dA)`
`= int_text(front surface) E.(dA) cos0^o`
` + int_text(curved surface) E.(dA) cos90^o`
` + int_text(rear surface) E.(dA) cos0^0`
`= int E dA + 0 + int E dA`
`= 2EA`
From gauss law
`oint vecE.vec(dS) =sum q_(en)/epsilon_0 = (sigmaS) /epsilon_0`
`E = sigma/(2epsilon_0)`