Solution :
given $I_1= I_2 = 300\;A$
$r= 1.5\;cm$
$\quad= 1.5 \times 10^{-2}\;m$
$l= 70\;cm$
$F= \large\frac{\mu_0}{4 \pi}.\frac{2I_1 I_2}{r}$
$\quad= \large\frac{10^{-7} \times 2 \times 300 \times 300}{1.5 \times 10^{-2}}$
$ \quad=0.12N/m,repulsive$
Answer : $ F=0.12N/m,repulsive$