# A small square loop of wire l is placed inside a square loop of wire of side L(L>>l).The loops are co-planer and their centres coincide.The mutual inductance of the system is proportional toA)l/LB)L2 /lC)L/lD) l2 /Lplease give me the complete and simple explanation to this answer...

Arun Kumar IIT Delhi
8 years ago
$M_{12}=M_{21}$
So we can put current on any of the conductor.
We put I on bigger loop because on small loop its effect will be almost constant (since l<<L).

Now its easier to solve this.

Thanks & Regards
Arun Kumar
IIT Delhi