Physics - Magnetism Question with Solution | TestHub

Let length of wire element at $P$ is $d$. Magnetic field at $P$, $\begin{array}{rl}& B=\frac{{\mu }_{0}i}{4\pi r}+0+\frac{{\mu }_{0}i}{4\pi r}\\ & B=\frac{{\mu }_0\times 5}{4\pi \times 5\times 10^{-2}}\times 2=\frac{{\mu }_0\times 200}{4\pi }\\ & B=2\times 10^{-5}\mathrm{T}\\ & F=iBdl\Rightarrow \frac{F}{dl}=iB=5\times 2\times 10^{-5}=10^{-4}{\mathrm{Nm}}^{-1}\end{array}$