THE ELECTROSTATICS AND MAGNETOSTATICS OF A CONDUCTING DISK

A method due to Copson for treating the electrostatics of a disk is modified so that each step can be understood physically. Using this method we easily find the capacitance 2a/pi and the electric polarizability 4a3/3pi of a conducting disk. We also find in closed form the Green's function along the axis and the self-force (the force due to induced charges) on a point charge on the axis. We similarly treat magnetic problems, finding the normal polarizability of a superconducting disk and the ''levitating'' force on a point monopole or vertical point dipole on the axis. All results are in closed form.