Two long parallel conductors carry currents i₁ = 3A and i₂ = 3A both are directed into the plane of paper. The magnitude of resultant magnetic field at point ‘P; is

$$\begin{gathered} \mathrm{Magnetic} \mathrm{field} \mathrm{due} \mathrm{to} \mathrm{the} \mathrm{conductors} \mathrm{at} \mathrm{P} \mathrm{are} \\ {\mathrm{B}}_1=\frac{{\mathrm{\mu }}_0\mathrm{i}}{2\mathrm{\pi }}\left(\frac{1}{5\times {10}^{-2}}\right) \mathrm{and} {\mathrm{B}}_2=\frac{{\mathrm{\mu }}_0\mathrm{i}}{2\mathrm{\pi }}\left(\frac{1}{12\times {10}^{-2}}\right) \\ \mathrm{as} \mathrm{they} \mathrm{are} \mathrm{perpendicular} \mathrm{resultant} \mathrm{magnetic} \mathrm{field} \\ \mathrm{B}=\sqrt{{\mathrm{B}}_1^2+{\mathrm{B}}_2^2} \\ \mathrm{here} \mathrm{i}=3 \mathrm{A} \mathrm{and} \mathrm{substiuting} \mathrm{B}=13\mathrm{\mu T} \end{gathered}$$