Two straight long conductors AOB and, COD are perpendicular to each other and carry currents i₁, and i₂. The magnitude of the magnetic induction at a point P at a distance d from the point O in a direction perpendicular to the plane, ABCD is

• A

  $\frac{{\mathrm{\mu }}_0}{2\mathrm{\pi d}}\left({\mathrm{i}}_1+{\mathrm{i}}_2\right)$

• B

  $\frac{{\mathrm{\mu }}_0}{4\mathrm{\pi d}}\left({\mathrm{i}}_1-{\mathrm{i}}_2\right)$

• C

  $\frac{{\mathrm{\mu }}_0}{2\mathrm{\pi d}}{\left({\mathrm{i}}_1^2+{\mathrm{i}}_2^2\right)}^{1/2}$

• D

  $\frac{{\mathrm{\mu }}_0}{2\mathrm{\pi d}}\left(\frac{{\mathrm{i}}_1{\mathrm{i}}_2}{{\mathrm{i}}_1+{\mathrm{i}}_2}\right)$