Two coils with self-inductance $1 H$ and $3 H$ are connected in series. Their mutual inductance is $5 H$. The equivalent self-inductance of the combination is: (in $H$)

An inductor coil of inductance $L$ is divided into two parts and both parts are connected in parallel. The net inductance is

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

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 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 . . . . . . $\text{mH}$.

Two inductors $L_1$ and $L_2$ are connected in parallel,and a time-varying current flows as shown. The ratio of currents $i_1/i_2$ at any time $t$ is: