A charged line like that shown in Fig. 21.25 extends from y = 2.50 cm to y = - 2.50 cm. The total charge distributed uniformly along the line is -9.00 nC.
(a) Find the electric field (magnitude and direction) on the x-axis at x = 10.0 cm.
(b) Is the magnitude of the electric field you calcula1ed in part (a) larger or smaller than the electric field 10.0 cm from a point charge that has the same total charge as this finite line of charge? In terms of the approximation used to derive E = Q/4πє0x2 for a point charge from Eq. (21.9), explain why this is so.
(c) At what distance x does the result for the finite line of change differ by 1.0% from that for the point charge?