Question

A coaxial cable consists of an inner cylindrical conductor of radius R1 -0.040 m on the axis of an outer hollow cylindrical conductor of inner radius R2 -0.080 m and outer radius R3 = 0.090 m. The inner conductor carries current 11 = 4,40 A in one direction, and the outer conductor carries current 12-4.40A in the opposite direction. What is the magnitude of the magnetic field at the following distances from the central axis of the cable? (0 = 4x * 10-7 T.m/A) (a) Atr-0.060 m (in the gap midway between the two conductors) (b) Atr=0.150 m (outside the cable)

Answer 1

la) @ At 0=0.060 l in the gap) len ie. hołal curent enclosed by amberian loop is 4.40 A J.B.de - Molene B = Mol arr 4 rx107 Tom/A X 0.40 A 211 X 0.060 2 1.466 x 105 1 b at distance ga 0.150 Clie. outside the cable) total current enclosed by ampenian loop Lene = ({1-12) - (4.40 -4.40) ( bolh are in opposite direction) at p=0.150 Coutside the cable) there fore magnetic field at will be zeso.