Question

A thin, flat washer is a disk with an outer diameter of 11.2 cm and a hole in the center with a diameter of 3.92 cm. It has a surface charge density of 5.37 μμC/m². What is the electric field on the axis of the washer at a distance of 28.6 cm from the center of the washer?

Answer 1

Expression for the area of the material of the disk is, = π ((0.056 m),-(0.0466 m). ) 3.03x10-3 m2 Expression for the charge density of the washer is, = 5.37×10-6 C/m2 Therefore, the electric field of the washer at distance of 28.6 cm is, 0.286 m 0.286)+R = (9×109)(5.37×10-6 C/m2)(Dr)| | (0.2800 2 ,(0.112)2 = 5。65 × 103 N/C Therefore, the electric field of the washer at distance of28.6 cm with no hole is, 0.286 m 0.286)+FR 0.286 m = (9×109)(5.37×10-6 C/m2)(Dr)| | (0.286)2+0.0392 - 9 -0.71x103 N/C Therefore, the required electric field is, E- E-E = (5.65 × 103 N/C)-(0.7 1x 103NC - 4.94 x103 N/C