RC ne cu show PHYS& 222 ICA 15: Sources of Magnetic Fields Name: 6. The figure shows a cross-section of a long conducting wire with inner radius a 2 cm and outer radius b = 4 cm. The cylinder carries a current out of the page with a uniform current density] = 3 x 10% A/m2. What is the strength of the magnetic field at the dot, which is at a radius r =3 cm from the central axis of the cylinder? innes vedios aan We want the magnetic field at the dot at radius r. (a)