Question

12-A spherical ball of charged particles has a uniform charge density. From Gauss’s Law, derive equations for the electric field magnitude as a function of radius, inside, and outside, of the ball. Sketch and label a graph to illustrate this variation. (c) A Geiger counter is used to detect ionizing radiation. For this device, a positively charged central wire is surrounded by a concentric, conducting cylindrical shell with an equal negative charge, creating a strong radial electric field. The shell contains a low-pressure inert gas, which when ionized by the radiation, leads to a detectable electric current between the wire and shell. What is the surface charge density on the central wire, where the radius of the central wire is 20 ?m, the radius of the inner shell is 1.4 cm, the length of the shell is 16 cm, and the magnitude of the electric field at the shell's inner wall is 2.9 × 104 N/C? Define variables used, give a clear labeled diagram, and discuss the role of symmetry and any assumptions required.

Answer 1