Question

The magnetic field $\overline{dB}$ due to a small current element dl at a distance $\overrightarrow{r}$ and carrying current ‘i’ is

• A. $\overline{dB}=\frac{{\mu }_0}{4\pi }i\left(\frac{\overline{dl}\times \overline{r}}{r}\right)$
• B. $\overline{dB}=\frac{{\mu }_0}{4\pi }{i}^2\left(\frac{\overline{dl}\times \overline{r}}{r^2}\right)$
• C. $\overline{dB}=\frac{{\mu }_0}{4\pi }{i}^2\left(\frac{\overline{dl}\times \overline{r}}{r}\right)$
• D. $\overline{dB}=\frac{{\mu }_0}{4\pi }i\left(\frac{\overline{dl}\times \overline{r}}{r^3}\right)$

Answer 1

The correct option is D $\overline{dB}=\frac{{\mu }_0}{4\pi }i\left(\frac{\overline{dl}\times \overline{r}}{r^3}\right)$

Bio-savert law - apply directly the statement of law