In Fig. 3, a thin glass rod forms a semicircle of radiusr7.1 cm. Charge is unifo
ID: 1658356 • Letter: I
Question
In Fig. 3, a thin glass rod forms a semicircle of radiusr7.1 cm. Charge is uniformly distributed along the rod, with +q = 4.4 pC in the upper half and-q =-4.4 pC in the lower half. What are the magnitude and direction of the electric field at the center of the semicircle? tq 0 -9 Figure 3. Semicircle electric dipoles Three positively charged particles lie on a horiontal line as shown in Fig. 1. Charges qi located at 1, g2 at 2, and q3 at 3. Charges qi and g3 are fixed in place. Charge q2 is free to move, but the net electric force on it from charges q1 and q3 happens to be zero. If d12-0.53, what is the ratio q341? d, 23 Figure 1. Three charged particles lie on a horizontal line.Explanation / Answer
(2) Electric force on q2 is = 0 means the electric field at q2 by both q1 and q2 is equal but opposite in direction so
Eq1 = Eq3
Kq1 / d12 = Kq3 / d23
q1 / .5 d23 = q3 / d23
q1 / .5 = q3
q3/q1 = 2