Physics
Physics
Problem
Two long, straight, parallel wires, labelled A and B, are fixed in a horizontal plane. The wires are separated by 6.0 cm and each carries a steady current of 10 A directed out of the page. A point P is located 4.0 cm directly above the midpoint of the line joining the two wires. (a) For each wire, state the direction of the magnetic field it produces at point P. Justify your answers using an appropriate rule. (b) Compare the magnitudes of the magnetic‐field contributions from the two wires at point P and explain the comparison using geometric reasoning. (c) Determine the direction of the net magnetic field at point P, supporting your conclusion with a clear vector argument. (d) The current in wire B is now reversed while the current in wire A remains unchanged. Qualitatively discuss whether a point exists on the perpendicular bisector of the two wires where the net magnetic field is zero, and explain your reasoning.Intuitive explanation
The key is recognizing that magnetic field superposition applies here—each current-carrying wire creates its own magnetic field, and you add them as vectors. Since both currents point the same direction (out of the page), their fields will have a specific geometric relationship at point P. Use the right-hand rule to find each field's direction, then combine them carefully, paying attention to the symmetry of the setup and how the distances from each wire to P determine the field magnitudes.
Intuitive explanation
The key is recognizing that magnetic field superposition applies here—each current-carrying wire creates its own magnetic field, and you add them as vectors. Since both currents point the same direction (out of the page), their fields will have a specific geometric relationship at point P. Use the right-hand rule to find each field's direction, then combine them carefully, paying attention to the symmetry of the setup and how the distances from each wire to P determine the field magnitudes.