Field and Wave Electromagnetics 2nd Edition by David Cheng

تمرين 17

Starting from the expression of A in Eq. (6-34) for the vector magnetic potential at a point in the bisecting plane of a straight wire of length 2L that carries a current I:
a) Find A at point P(x, y, 0) in tlie bisecting plane of two parallel wires each of length 2L, located at y = ± d/2 and carrying equal and opposite currents, as shown in Figure.
b) Find A due to equal and opposite currents in a very long two-wire transmission line.
c) Find B from A in part (b), and check your answer against the result obtained by applying Ampere's circuital law.
d) Find the equation for the magnetic flux lines in the xy -plane.
Figure: Parallel wires carrying equal and opposite currents