Figure given in the question is a cross-sectional view of a coaxial cable. The centre conductor is surrounded by a rubber layer, which is surrounded by an outer conductor, which is surrounded by another rubber layer. The current in the inner conductor is `1.0 A` out of the page, and the current in the outer conductor is 3.0A into the page. Determine the magnitude and direction of the magnetic field at points a and b.

Answer

[`200 mu T` toward the top of the page, `133 mu T` toward the bottom of the page]