Two conducting circular loops of radii a and b are placed in the same plane with their centre coinciding. If a >> b, the mutual inductance M between then will be directly proportional to:

$\frac{a^2}{b}$ $\frac{a}{b}$ $\frac{b}{a}$ $\frac{b^2}{a}$

$\frac{b^2}{a}$

The correct answer is Option (4) → $\frac{b^2}{a}$