The equivalent inductance between $A$ and $B$ is ..... $H$.

Two inductors of $80 \ mH$ each are joined in parallel. The current passing through the combination is $2.1 \ A$. The energy stored in this combination of inductors is

In the given circuit below, the inductance values of $L_1$, $L_2$, and $L_3$ are the same. The magnetic energy stored in the entire circuit is $U_t$ and that stored in the $L_2$ inductor is $U_l$. The ratio $U_t/U_l$ is . . . . . . . (Ignore the mutual inductance, if any.)

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 inductances are connected as shown in the figure. The equivalent inductance between $A$ and $B$ is (in $H$)

Two inductors,each of inductance $L$,are connected in parallel. One more inductor of value $5 \text{ mH}$ is connected in series with this configuration,and the effective inductance is $15 \text{ mH}$. The value of $L$ is . . . . . . $\text{mH}$.