60 O In Fig. 21-43, six charged particles surround particle 7 at ra dial distances of either d = 1.0 cm or 2d, as drawn. The charges are q1 = +2e,92 = +4e, q3 = +e,q4= +4e,q5 = +2e,q6 = +8e,q7 = +6e with e = 1.60 x 10-19C. What is the magnitude of the net electro static force on particle 7? Figure 21-43 Problem 60. 4.

Given the two charges shown in Fig. 16–68, at what posi- tion(s) x is the electric field zero? Õ+ -Q/2 FIGURE 16-68 Problem 63.

6 In Fig. 22-27, two identical circu- lar nonconducting rings are centered on the same line with their planes perpendicular to the line. Each ring has charge that is uniformly distrib- uted along its circumference. The rings each produce electric fields at points along the line. For three situations, the charges on rings A and B are, respectively, (1) qo and 9o, (2) -90 and -90, and (3) - and qo. Rank the situations according to the magnitude of the net electric field at (a) point P1 midway between the rings, (b) point P, at the center of ring B, and (c) point P3 to the right of ring B. greatest first. P, P3 Ring A Ring B Figure 22-27 Question 6.

In Fig.89 the metallic wire has a uniform linear charge density λ = 4 x 10-⁹C/m, the rounding radius R=10cm is much smaller than the length of the wire. Find the magnitude of the electric field at point "0". 001|2 R Fig-89

(a) Calculate the strength and direction of the electric field, E, due to point charge of 2.5 nC at a distance 4 mm from the charge. For the direction, consider the line joining the point charge and point at the distance 4 mm. The direction on this line away from the charge is positive and the direction towards the charge is negative.

•27 Go In Fig. 22-51, two curved plastic rods, one of charge +q and the other of +4 charge -q, form a circle of radius R = 8.50 cm in an xy plane. The x axis passes through both of the connecting points, and the charge is distributed uniformly on both rods. If q = 15.0 pC, what are the (a) magnitude and (b) direction (relative to the positive direction of the x axis) of the electric field E produced at P, the -9 Figure 22-51 Problem 27. center of the circle?

(I) Determine the magnitude and direction of the electric force on an electron in a uniform electric field of strength 2460 N/C that points due east.

(12-15) Consider two concentric conducting spherical shells. Inner shell carries an excess charge of +2 µC and outer shell carries +2 µC. In the figure, the inner shell has an inner radius of 0.1 m and an outer radius of 0.2 m, and the outer shell has an inner radius of 0.38 m and an outer radius of 0.5 m. d

13. (II) Three positive particles of equal charge, +17.0 μC, are located at the cor- ners of an equilateral triangle of side 15.0 cm (Fig.21-55 ). Calculate the magnitude and direction of the net force on each particle due to the other two. Figure 21-55 +170 μC 15.0 cm 15.0 cm +170 μC 15.0 cm +170 μC Problem 130.