Volu 38. (II) (a) Determine the electric field E at the origin 0 in Fig. 21-59 due to the two charges at A and B. (b) Repeat. but let the charge at B be reversed in sign. FIGURE 21-59 Problem 38. 39. (II) Draw, approximately, the electric field lines emanating from a uniformly charged straight wire whose length f is not great. The spacing between lines near the wire should be much less than f. [Hint: Also consider points very far from the wire.] 40. (II) Two parallel circular rings of radius R have their centers on the x axis separated by a distance & as shown in Fig. 21-60 If each ring carries a uniformly distributed charge Q, find the electric field, E(x), at points along the x axis. FIGURE 21-60 Problem 40. 41. (II) You are given two unknown point charges, Q, and Q2 At a point on the line joining them, one-third of the way from 21 to 22, the electric field is zero (Fig ? the ratio 21/Q2