Question

A long, straight solid cylinder of radius R2 carries a current. Although the current

density (i.e., the current per unit cross sectional area) is symmetrical about the

axis of the cylinder, it is not constant; the current density is J0 for r < R1, and 2J0

for R1 < r < R2. (The direction of the current is the same everywhere within the

cylinder.) Find an expression for the magnetic field (a) for r < R1, (b) for R1 < r <

R2, and (c) outside the cylinder, where r > R2.

Answer 1