Flux and nonconducting shells. A charged particle is suspended at the center of
ID: 1494692 • Letter: F
Question
Flux and nonconducting shells. A charged particle is suspended at the center of two concentric spherical shells that are very thin and made of nonconducting material. Figure (a) shows a cross section. Figure (b) gives the net flux ? through a Gaussian sphere centered on the particle, as a function of the radius r of the sphere. (The vertical axis is marked in increments of 2.0x105 N·m2/C with ?s = 1.0x106N·m2/C )
(a) What is the charge of the central particle?
_____ µC
(b) What is the net charge of shell A?
_____µC
(c) What is the net charge of shell B?
_____µC
Explanation / Answer
(a) For r < RA , = Qc/o = 4 * 105 Wb
=> central charge, Qc = (4 * 105) * (8.854 * 10-12) = 3.5 µC
(b) For RA < r < RB , = (Qc + QA)/o = -8 * 105 Wb
=> Net charge on shell A, QA = [(-8 * 105) * (8.854 * 10-12)] - 3.5 = -10.6 µC
(c) For r > RB , = (Qc + QA + QB)/o = 1.2 * 106 Wb
=> Net charge on shell B, QB = [(1.2 * 106) * (8.854 * 10-12)] - 3.5 + 10.6 = 17.7 µC