Question

The magnetic field at center, $P$ will be

• A. $\frac{{\mu }_0}{4\pi }$
• B. $\frac{{\mu }_0}{\pi }$
• C. $\frac{{\mu }_0}{2\pi }$
• D. $4{\mu }_0\pi$

Answer 1

The correct option is C $\frac{{\mu }_0}{2\pi }$

$B=\frac{{\mu }_0}{4\pi }\frac{2i_1}{\frac{r}{2}}-\frac{{\mu }_0}{4\pi }\frac{2i_2}{\frac{r}{2}}=\frac{{\mu }_0}{4\pi }\frac{4}{r}(i_1-i_2)=\frac{{\mu }_0}{4\pi }\frac{4}{5}(5-2.5)=\frac{{\mu }_0}{2\pi }$