Question

Mutual inductance $M$ between two concentric coils of radii $1m$ and $2m$ is

• A. $\frac{{\mu }_0\pi }{2}$
• B. $\frac{{\mu }_0\pi }{4}$
• C. $\frac{{\mu }_0\pi }{8}$
• D. $\frac{{\mu }_0\pi }{10}$

Answer 1

Answer: (B)

Here, $r_1=1m,r_2=2m$
Mutual inductance, $M=\frac{{\mu }_0\pi r_1^2}{2r_2}$
$=\frac{{\mu }_0\pi \times 1}{2\times 2}$
$=\frac{{\mu }_0\pi }{4}$