$A$ coil of inductance $L$ is divided into four equal parts and all the parts are connected in parallel. The effective inductance of the combination is

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?

Initially,the switch $S$ is open and the energy stored in the inductance $L$ connected in series with the battery is $E$. Now,the switch $S$ is closed. The energy stored in both the inductors after a long time 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.)

The inductance between $A$ and $D$ is

Three inductances are connected as shown below. Assuming no coupling,the resultant inductance will be $H$.