Figure P28.62 shows an end view of two long, parallel wires perpendicular to the xy-...

Figure P28.62 shows an end view of two long, parallel wires perpendicular to the xy-plane, each carrying a current I but in opposite directions. (a) Copy the diagram, and draw vectors to show the field of each wire and the net field at point P. (b) Derive the expression for the magnitude of at any point on the x-axis in terms of the x-coordinate of the point. What is the direction of ? (c) Graph the magnitude of at points on the x-axis. (d) At what value of x is the magnitude of a maximum? (e) What is the magnitude of when x >> a?