Question

In a conductive and infinite cylindrical wire, the radius R is flowing from right to left, see drawing. The current density across the cross-sectional area of ​​the wire is not uniform but varies by the following expression : J (r) = b · r

Where r is the distance from the center of the cylinder cross-section (radius axis) and b is constant.

A) Calculate the size of the general current flowing in the wire (I).

B) Calculate the magnitude and direction of the magnetic field outside the wire (r> R).

Answer 1