A point charge is held from the centre of a thick spherical metal shell that carries…
PHYSICS · Multi-part · Fermi University Physics · Electricity, Magnetism & Electromagnetism · Electrostatic fields and potential · Conductors, capacitance and boundary-value electrostatics
Electricity, Magnetism and Electromagnetism, Ch Conductors, screening and capacitance
Problem
A point charge +4.0nC is held 1.0cm from the centre of a thick spherical metal shell that carries no net charge. The shell's inner radius is 3.0cm and its outer radius is 5.0cm. There is vacuum inside the cavity and outside the shell, no other charges are anywhere near, and the shell has reached electrostatic equilibrium. Distances r are measured from the centre of the shell. Predict, with a reason in each case:
((a)) the total charge on the inner surface of the shell, and whether it is spread uniformly;
((b)) the total charge on its outer surface, and whether it is spread uniformly;
((c)) the magnitude of the electric field at r=4.0cm, a point inside the metal;
((d)) the magnitude and direction of the electric field at r=10.0cm;
((e)) the charge on the outer surface and the field at r=10.0cm once the outer surface is connected to earth.