Question

The magnetic field at centre, $P$ 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

Answer: (C)

The correct option is $C\frac{{\mu }_0}{2\pi }$
$B=\frac{{\mu }_{0}2i_1}{4\pi r_r}-\frac{{\mu }_{0}2i_2}{4\pi r_r}$
$=\frac{{\mu }_{0}4}{4\pi r}\left(i_1-i_2\right)$
$=\frac{{\mu }_{0}4}{4\pi 5}(5-2.5)$
$=\frac{{\mu }_0}{2\pi }$