1. The problem statement, all variables and given/known data The figure represents a section of a circular conductor of nonuniform diameter carrying a current of 5.00 A. The radius of cross-section A1 is 0.400 cm. [URL=http://img97.imageshack.us/i/img01mn.jpg/][PLAIN]http://img97.imageshack.us/img97/7220/img01mn.th.jpg[/URL][/PLAIN] 2. Relevant equations (a) What is the magnitude of the current density across A1 ? (b) If the current density across A2 is one-fourth the value across A1, what is the radius of the conductor at A2 ? 3. The attempt at a solution J=I/A= 5.00A/pi(.004)^2=99,472.8 A m^2 Could someone help please? I am doing this the right way?