$A$ 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

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 of $60 mH$ each are joined in parallel. The current passing through this combination is $2.2 A$. The energy stored in this combination of inductors in joule is

Two pure inductors each of self inductance $L$ are connected in parallel but are well separated from each other. The total inductance is

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 $H$)

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 $mH$)