Two very long coaxial cylindrical conductors are shown in cross-section below. The inner cylinder has radius a = 2 cm and caries a total current of I1 = 1.0 A in the positive z-direction (pointing out of the page). The outer cylinder has an inner radius b = 4 cm, outer radius c = 6 cm and carries a current of I2 = 2.0 A in the negative z-direction (pointing into the page). You may assume that the current is uniformly distributed over the cross-sectional area of the conductors. a) Calculate the magnitude and direction of the magnetic field at a radius of r=20 cm. b) Calculate the magnitude and direction of the magnetic field at a radius of r=3 cm.

Two very long coaxial cylindrical conductors are shown in cross-section below. The inner cylinder has radius a = 2 cm and caries a total current of I1 = 1.0 A in the positive z-direction (pointing out of the page). The outer cylinder has an inner radius b = 4 cm, outer radius c = 6 cm and carries a current of I2 = 2.0 A in the negative z-direction (pointing into the page). You may assume that the current is uniformly distributed over the cross-sectional area of the conductors. a) Calculate the magnitude and direction of the magnetic field at a radius of r=20 cm. b) Calculate the magnitude and direction of the magnetic field at a radius of r=3 cm.