11 An infinitively long coaxial cable is made of non-conducting material. The inner cylinder with radius 2m, is made of a material H = Ho, &r= 2, and carries a non-uniform current with current density J= 5r in the z direction. The outermost cylindrical shield with inner radius 3m, and outer radius 4 m, is made of a material with u= lo,Er = 9, and carries an uniform current density J = -2 A/m2, i.e., in the-z direction. The space between the cylinders is filled with air (3m>r > 2m). Outside r > 4m, the medium is vacuum. Find B(magnitude and direction) in each region. Sketch B(r)

Fig: 1

Fig: 2