Consider a thin ring of radius a with uniform charge density and total charge Q. The ring is cut in half across the diameter and the two halves superimposed to double the effective charge density. Calculate the electric field at a point 4a from the ring along the x-axis with the ring in the y-z plane and the center of the arc at the origin. The half-ring is symmetric about the z-x plane extending only in the positive z-direction.
Consider a thin annular disk of outer radius 2a and inner radius a with a uniform charge density,s. The total charge is Q. (a) Calculate the field on one side of the disk as a function of the distance x from the disk along the centerline. (b) Make a plot of the dimensionless field strength, E?o /s , as a function of dimensionless distance x/a from zero to 5.