N charges on a circle ***
N point charges, each with charge Q/N, are evenly distributed around a circle of radius R. What is the electric field at the loca- tion of one of the charges, due to all the others? (You can leave your answer in the form of a sum.) In the N → ∞ limit, is the field infinite or finite? In the N → ∞ limit, is the force on one of the charges infinite or finite?