PHYSICS 8B Midterm: physics8B-sp2018-mt1-Speliotopoulos-soln
Document Summary
In order to nd the electric eld at the two given points, we will use gauss". The charge distribution in this problem in spherically symmetric, so we will choose our. Gaussian surfaces to be spheres sharing a common center with the conducting spheres of the problem. Let"s give our rst gaussian sphere a radius of r1 since we are interested in the electric eld at this distance. Whatever the electric eld is at a distance r1, it must be pointing radially outward. This means the electric eld lines are perpendicular to the surface (parallel to n), and the electric ux integral includes the full surface area of our gaussian sphere. As for qenc, our surface only encloses the charged sphere of radius a. Since r1 is below the positively charged sphere, the electric eld must point downward: As before, we take our gaussian surface to be a sphere of radius r2.
