Two long wires carrying current , and are arranged as shown in the figure. The one carrying current is along the x-axis. The other carrying current is along a line parallel to the y-axis given by x = 0 and z = d. Find the force exerted at because of the wire along the x-axis.
Firstly, we need to find the direction of the magnetic field caused by one wire on a specific point on the other wire, then determine the magnetic force on the wire carrying current.
According to Biot-Savart law, the magnetic field is parallel to dl x r whereas I dl direction is along the direction of flow of current, but it can also be found out by using the right-hand thumb rule.
Here the direction of the magnetic field at , due to the wire carrying I1 current is
So the direction of is along the Y-direction direction of the magnetic force exerted at because of the wire along the x-axis is
So the magnetic field due to the wire is along the y-axis. The second wire is along the y-axis and hence, the force is zero.