A uniform thin circular ring of radius 2 millimeter has uniformly distributed charge 2.00 mC. Obtain the electric field on the axis of the ring, perpendicular to the plane of the ring, at a distance of 2 centimeter from the center of the ring. At this distance, I claim that I can think of the small ring as a point charge and use the formula for a point charge and compute the electric field. Determine how much is the percentage error if I make that claim? Find at what minimum distance do you think my claim would be justifiable? Why?