$B=\frac{\mu_{0} i}{4 \pi r}+0+\frac{\mu_{0} i}{4 \pi r}$

$=\frac{\mu_{0} \times 5}{4 \pi \times 5 \times 10^{-2}} \times 2$

$=\frac{\mu_{0}}{4 \pi} \times 200$

$=2 \times 10^{-5} T$

Consider the length of wire element at $P$ is $dl$.

The force per unit length at $P$ is,

$F=i B d l$

$\frac{F}{d l}=i B$

$=5 \times 2 \times 10^{-5}$

$=10^{-4} N / m$