Question

The magnetic field at the origin due to a current element $\overrightarrow{idl}$ placed at a point with vector position $\overrightarrow{r}$ is

• A. $\frac{\mu_0 i}{4\pi} \frac{\vec{dl} \times \vec{r}} {{r^3}}$
• B. $\frac{\mu_0 i}{4\pi}\frac{\vec{r} \times \vec{dl}}{r^3}$
• C. $\frac{\mu_0 i}{4\pi} \frac{\vec{dl} \times \vec{r}} {{r^2}}$
• D. $\frac{\mu_0 i}{4\pi}\frac{\vec{r} \times \vec{dl}}{r^2}$

Answer 1

Answer: (A)

$\frac{\mu_0 i}{4\pi} \frac{\vec{dl} \times \vec{r}} {{r^3}}$

Answer 2

The correct option is (A):$\frac{\mu_0 i}{4\pi} \frac{\vec{dl} \times \vec{r}} {{r^3}}$