Fundamentals of Engineering Electromagnetics 1st Edition by David Cheng

Exercise 3

A short conducting wire carrying a time-harmonic current is a source of electromagnetic waves. Assuming that a uniform current i ( t ) = I o cos t flows in a very short wir e d placed along the z -axis,
a) determine the phasor retarded vector potential A at a distance R in spherical coordinates, and
b) find the magnetic field intensity H from A.