College Physics 10th Edition by Raymond Serway,Chris Vuille

Exercise 5

Two long, parallel wires separated by a distance 2 d carry equal currents in the same direction. An end view of the two wires is shown in Figure P19.54, where the currents are out of the page. (a) What is the direction of the magnetic field at P on the x -axis set up by the two wires (b) Find an expression for the magnitude of the field at P. (c) From your result to part (b), determine the field at a point midway between the two wires. Does your result meet with your expectation Explain.