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

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

$A$ circuit contains two inductors of self-inductance $L_1$ and $L_2$ connected in series as shown in the figure. If $M$ is the mutual inductance between them,then the effective inductance of the circuit will be

Two identical induction coils,each of inductance $L$,are joined in series and placed very close to each other such that the winding direction of one is exactly opposite to that of the other. What is the net inductance?

Two coils of self-inductance $L_{1}$ and $L_{2}$ are connected in series. If the mutual inductance of the coils is $M$,the equivalent self-inductance of the combination shown in the figure will be:

Two identical inductors, each of inductance $L$, are connected in two different configurations $P$ and $Q$, through which a time-varying current $I(t)$ flows. The induced emf between points $a$ and $b$ for configuration $P$ is $E_P$ and that for configuration $Q$ is $E_Q$. The ratio $E_P/E_Q$ is: [Neglect the effect of mutual inductance.]