Learning Goal: use the definition of electric field to analyze the field created by a continuous charged arc. A total charge Q = 4.30 C is distributed uniformly over a quarter-circle arc of radius a = 8.00 cm, as shown. y be X The semi-circular arc shown in the figure has charge 2Q = 8.60 C, which is twice the charge of the quarter-circle arc. Esemi y What is the magnitude Esemi of the electric field at the origin produced by the semi-circular arc? = 20 N/C