A point charge q = -8 μC is surrounded by two thick, conducting spherical shells of inner and outer radii
a1 = 0.3 m, a2 = 0.4 m, a3 = 0.7 m, and a4 = 0.8 m respectively. The inner shell is uncharged; the outer
shell has a net charge Q = -10 μC. At this point in the problem, the potential at infinity is unspecified.
(c) V(a2) - V(a3) = ____________________ V
E = kQ/r^2
Guass’ Law: ϕ= ʃE·dA
V0 = - ʃE·dl
HELP: Identify the equivalent point-charge that gives the same electric fields everywhere in the region a2 < r < a3 as the specified charge distribution.
HELP: Use the electric potential function that corresponds to the equivalent point-charge problem.
The Attempt at a Solution
Electric field of the sphere at a2:
E = k(-8uC)/(.4^2) = -449500 N/C
Im stuck. I figured out the first two problems but I am not sure how to relate the electric field to the potential, and I am not sure how to get the equivalent point charge. I assume I need to use guass' law to find the equivalent point charge but my queastion is do I just use the difference of a2 and a3 for the radius?