Question

The vector form of Biot-Savarts law for a current carrying element is

• A. $d\vec{\mathbf{B}}=\frac{{\mu }_0}{4\pi }\frac{Id\vec{1}\sin \varphi }{r^2}$
• B. $\vec{\mathbf{B}}=\frac{{\mu }_0}{4\pi }\frac{Idl\vec{\mathbf{r}}}{r^2}$
• C. $d\vec{\mathbf{B}}=\frac{{\mu }_0}{4\pi }\frac{Id\vec{1}\times \vec{\mathbf{r}}}{r^3}$
• D. $d\vec{\mathbf{B}}=\frac{{\mu }_0}{4\pi }\frac{Id\vec{1}\times \vec{\mathbf{r}}}{r^2}$

Answer 1

Answer: (D)

Biot-Savaits law, $dB=\frac{{\mu }_0}{4\pi }\frac{Idl\sin \theta }{r^2}$ In vector form, $d\overrightarrow{\mathbf{B}}=\frac{{\mu }_0}{4\pi }\frac{Id\overrightarrow{\mathbf{l}}\times \hat{\mathbf{r}}}{r^2}$