Question

Radii of two conducting circular loops are b and a respectively where b > > a. Centers of both loops coincide but planes of both loops are perpendicular to each other. The value of mutual inductance for these loops

• A. $\frac{\mu_0 \pi a^2}{2b}$
• B. $\frac{\mu_0 \pi b^2}{2a}$
• C. zero
• D. $\frac{\mu_0 \pi ab}{2(a+ b)}$

Answer 1

Answer: (C)

zero

Answer 2

At the position of smaller loop, magnetic field due to larger loop is parallel to the plane of smaller loop. Due to larger loop, magnetic flux with smaller loop is zero. Hence, mutual induction is zero.
$\phi =M \,i_{2}$
$\Rightarrow \,0 =M i_{2}$
$\Rightarrow \, M =0$