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 $H$)

The equivalent inductance between $A$ and $B$ is equal to

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 $mH$)

An inductor coil of inductance $L$ is cut into two equal parts and both the 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 $H$)

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