Question

A current I is flowing through the loop. the direction of the current and the shape of the loop are as shown in the figure. The magnetic field at the centre of the loop is $(MA=R,MB=2R,$ angle $DMA={90}^o)$

• A. $\frac{7{\mu }_{0}i}{16R}$, but out of the plane of the paper.
• B. $\frac{5{\mu }_{0}i}{16R}$, but out of the plane of the paper.
• C. $\frac{7{\mu }_{0}i}{16R}$, but into of the plane of the paper.
• D. $\frac{5{\mu }_{0}i}{16R}$, but into of the plane of the paper.

Answer 1

The correct option is A $\frac{7{\mu }_{0}i}{16R}$, but out of the plane of the paper.

$\frac{{\mu }_{0}i\times \frac{3\pi }{2}}{4\pi R}+\frac{{\mu }_{0}i\frac{\pi }{2}}{4\pi \times 2R}=\frac{7{\mu }_{0}i}{16R}$