Alternating Current Question 6

Question 6 - 29 January - Shift 1

Find the mutual inductance in the arrangement, when a small circular loop of wire of radius ’ $R$ ’ is placed inside a large square loop of wire of side $L$ $(L»R)$. The loops are coplanar and their centres coincide :

(1) $M=\frac{\sqrt{2} \mu_0 R^{2}}{L}$

(2) $M=\frac{2 \sqrt{2} \mu_0 R}{L^{2}}$

(3) $M=\frac{2 \sqrt{2} \mu_0 R^{2}}{L}$

(4) $M=\frac{\sqrt{2} \mu_0 R}{L^{2}}$

Show Answer

Answer: (3)

Solution:

Formula: Magnetic Flux

$\phi=Mi$

$\phi=(\mathbf{B A})$

$\phi=\pi R^{2}\left(4 \frac{\mu _0}{4 \pi} \frac{i}{\left(\frac{L}{2}\right)} \sqrt{2}\right)$

$\Rightarrow M=\frac{2 \sqrt{2} \mu _0 R^{2}}{L}$