When finding the electric field intensity due to an infinite sheet of charge using GUASSS THEOREM…We?
Use a cylinder because the top and bottom are parallel to the sheet charge. Then make the length of teh cylinder very small so all of the electric field must pass through either the top or bottom of teh cylinder. The integral over the closed surface is just the electric field times the area of teh top and/or bottom of the cylinder 9the electric field is considered constant over the top and bottom of the cylnder). If you used a sphere, then you’d hae to consider the distance to the sphere from each point on the charge sheet and the angle a vector from each point on the sheet makes with each point on the sphere – the integral would be very messy,.
