Three infinitely-long conductors carrying currents $I_1,I_{2}and{I}_3$  lie perpendicular to the plane of the paper as shown below. If the value of integral $\oint { }_C\overrightarrow{B}.d\overrightarrow{\mathcal{l}}$  for the loops ${\text{C}}_{\text{1}}{\text{,C}}_{\text{2}}{\text{\hspace{0.17em}and\hspace{0.17em}C}}_{\text{3}}$  are ${\text{2μ}}_{\text{0}}{\text{,4μ}}_{\text{0}}{\text{\hspace{0.17em}and\hspace{0.17em}μ}}_{\text{0}}$   in SI units, respectively, then