# 2) A very large number of very long wires are arranged to form a current-carrying “ribbon,”…

2) A very large number of very long wires are arranged to form a current-carrying “ribbon,” as shown in the figure below. Each wire can be assumed to have negligible radius and carries the same current I (in the same direction). The ribbon is oriented in the xy-plane, at z =0. Hint: This problem has planar symmetry, so consider how you might apply Ampere’s Law. Also note that this problem is equivalent to an infinite current-carrying sheet with surface a surface current density given by K =(n. , where n is the number of wires per unit length. poodddddddd X a) What magnetic field (magnitude and direction) is produced in the region above this ribbon (i.e., for positive values of z)? b) What is the magnetic field below the ribbon (i.e., negative values of z)? c) Suppose you add a second identical ribbon, parallel to the first but carrying a current I in the opposite direction. If the second ribbon is located some fixed distance above the first (say +zo), then what is the magnetic field both between, and outside the parallel set of ribbons?
0 0