Assume a uniformly charged ring of radius R and charge Q produces an electric field Ering at a point Pon its axis, at distance x away from the center of the ring. Now the same charge Q is spread uniformly over the circular area the ring encloses, forming a flat disk of charge with the same radius. How does the field Edisk produced by the disk at P compare with the field produced by the ring at the same point? (a) Edisk < Ering (b) Edisk = Ering (c) Edisk > Ering (d) impossible to determine