Question

Two long parallel wires are 10cm apart and carry currents of 6A and 4 A. What is the field at B at 4A carrying wire due to 6A wire

Answer 1

magnetic field =$\frac{\mu_oi}{2\pi r}=\frac{4\pi\times10^{-7}\times6}{2\pi\times0.1}=12\times10^{-6}=1.2\times10^{-5}$