A current carrying wire is placed in a medium having the relative permeability 2. Then find the correct form of biot-savart law in this medium.
1
\(d\vec B = \frac{{{\mu _0}}}{{4\pi }}\frac{{I\left( {d\vec l \times \vec r} \right)}}{{{r^3}}}\)
2
\(d\vec B = \frac{{{\mu _0}}}{{4\pi }}\frac{{I\left( {d\vec l \times \vec r} \right)}}{{{r^2}}}\)
3
\(d\vec B = \frac{{{\mu _0}}}{{4\pi }}\frac{{Id\vec l}}{{{r^2}}}\)
4
\(d\vec B = \frac{{{\mu _{0\;}}\;}}{{2\pi }}\frac{{I\left( {d\vec l \times \vec r} \right)}}{{{r^3}}}\)