Two identical coils of inductance $L$ joined in series are placed very close to each other such that the winding direction of one coil is exactly opposite to that of the other. The net inductance is

Two inductors $A$ and $B$ when connected in parallel are equivalent to a single inductor of inductance $1.5 \ H$,and when connected in series are equivalent to a single inductor of inductance $8 \ H$. Find the difference in the inductances of $A$ and $B$. (in $H$)

Two coils of self-inductances $6 mH$ and $8 mH$ are connected in series and are adjusted for the highest coefficient of coupling. The equivalent self-inductance $L$ for the assembly is approximately: (in $mH$)

Three coils of inductance $L_1 = 2 \ H$, $L_2 = 3 \ H$, and $L_3 = 6 \ H$ are connected such that they are separated from each other. To obtain an effective inductance of $18/11 \ H$ between points $A$ and $B$, which of the following figures is correct?

$A$ circuit contains two inductors of self-inductance $L_1$ and $L_2$ connected in series as shown in the figure. If $M$ is the mutual inductance between them,then the effective inductance of the circuit will be

Three coils of inductance $L_1 = 2 \ H$, $L_2 = 3 \ H$, and $L_3 = 6 \ H$ are connected such that they are separated from each other. To obtain an effective inductance of $1 \ H$, which of the following combinations, as shown in the figure, is correct?