According to Biot - Savart law, the magnetic field \(d\vec{B}\) produced by a current element \(\vec{dl}\) at a distance, \(\vec{r}\), assuming that current i flows through the element, is
1
\(4\pi \mu_0 i \dfrac{\vec{r}\times \vec{dl}}{r^3}\)
2
\(\dfrac{\mu_0i}{4\pi} \dfrac{\vec{r} \times \vec{dl}}{r^2}\)
3
\(\dfrac{\mu_0 i}{4\pi} \dfrac{\vec{dl}\times \vec{r}}{r^3}\)
4
\(4\pi \mu_0 i \dfrac{\vec{dl}. \vec{r}}{r^3}\)
5
Not Attempted