A coaxial cable consists of a wire of radius 'a' surrounded by a concentric conducting sleeve of inner radius 'b' and outer radius 'c'. A current flows in the wire of radius 'a' out of the page; this current is spread uniformly over the cross section of the wire. An equal current flows in the opposite direction in the sleeve;
1. Imagine a small cylindrical permanent magnet floating above a superconducting tin disk bathed in liquid helium at around 1.2 K. The magnet was placed on the disk, and the latter was cooled below its transition temperature, at which point the magnet spontaneously jumped into the air. Explain what happened. This same kind of ma
1.) A coaxial cable consists of central conducting wire embedded in a cylindrical insulating core, which is then surrounded by another outer conducting cylinder usually made of wrapped aluminum foil or copper braid. Suppose such a cable carries a current of 36.5A flowing in one direction along the wire and 2.19A flowing in the o