When we find the electric field due to a continuous charge distribution, we imagine slicing that source up into small pieces, finding the electric field produced by the pieces, and then integrating to find the electric field. Let's see what happens if we break a finite rod up into a small number of finite particles. The figure shows a rod of length 2l carrying a uniform charge Q modelled as two particles of charge Q/2. The particles are at the ends of the rod. Find an expression for the electric field at point A located at a distance l above the midpoint of the rod by using the exact expression
