Hello everyone.... I'm suppose to determine the charge density on either plate. I attached a file which shows the diagram of what i'm talking about. I understand there is no feild inside the conducting plate, and the only area penetrated by the feild lines is the surface A' projtecting into the space between the plates. I appplied Gauss's law to the left plate... d = delta. EoEA = q EoEA' = dA' E = d/Eo I understand up to this point...then they say, Notice that the feild between the two plates in this example is exactly twice the feild due to a thin sheet of charge. Now i'm lost... why is it exactly twice? Then they say... E = E1 + E2 = d/[2Eo] + d/[2Eo] = d/Eo; Why is it d/[2Eo] and not d/Eo ? Also why is there 2 Electrical feilds? Thanks.