The magnitude j(r) of the current density in a certain cylindrical wire is given as a function of radial distance from the center of the wire's cross section as j(r) = br, where r is in meters, j is in amperes per square meter, and b = 2.35 ✕ 105 a/m3. this function applies out to the wire's radius of 2.00 mm. how much current is contained within the width of a thin ring concentric with the wire if the ring has a radial width of 11.5 μm and is at a radial distance of 1.20 mm?

The two metal spheres in the figure are connected by a metal wire with w switch in the middle. initially the switch is open. sphere 1, with the larger radius, i'd given a positive charge. sphere 2, with the smaller radius, is neutral. then the switch is closed. afterward, sphere 1 has charge q1, is at potential v1 and the electric field strength at its surface is e1. the values for sphere 2 are q2, v2, and e2. a. is v1 < ,> , or = to v2? explain. b. is q2 < , > , or = explain? c. is e1 < ,> ,or = to e2? explain?