Question

"Consider a conducting wire that runs along the central axis of a hollow conducting cylinder. Such an arrangement, called a coaxial cable, has many applications in telecommunications. In such a cable a current I runs in one direction along the hollow conducting cylinder and is spread uniformly over the cylinder's cross-sectional area. An equal current runs in the opposite direction along the central wire. How does the magnitude of B of the magnetic field outside such a cable depend on the distance r from the central axis of the cable

Answer 1

The magnetic field is zero at every point outside the cable.This is because the magnetic field generated by the wire and the magnetic field generated by the hollow cylinder are equal but they cancel each other because they act in opposite direction

Step-by-step explanation: