Three infinitely long wires, each carrying a current 1 A, are placed such that one end of each wire is at the origin, and, one of these wires is along x-axis, the other along y-axis and the third along z-axis. Magnetic induction at point −2 m, 0,   0 due to the system of these wires can be expressed as:

The magnetic field due to wire placed along x-axis will be zero. The point under consideration is semi finite position of the wires placed along y-axis and z-axis.Magnetic field due to wire placed along y-axis,B→y=μ0I4πr  k^Magnetic field due to wire placed along z-axis,B→z=μI4πr  −j^Hence, net magnetic field, B→=μ0I2πr  k^−j^After substituting the values, we get,B→=μ08π  k^−j^T