$B=\frac{{}_0\text{I}}{2r}=\frac{u_0{10}^{-7}10}{2(7)+(3)}=\frac{1\mathrm{.}26{10}^{-5}}{46\mathrm{.}98}=2\mathrm{.}68{10}^{-7}T$

$11-12.$ Two wires are in the shape of a plus sign. Each wire carries $10$ A of current. What is the Total Magnetic field at point $P?$

$($:$(5\mathrm{.}54{10}^{-4}(T))+6\mathrm{.}68{10}^{-7}(T)$