Calculate the equivalent inductance $L_{\mathrm{eq}}$ of two ideal inductors, $L_{1}$ and $L_{2},$ connected in series in a circuit. Assume that their mutual inductance is negligible. [Hint: Imagine replacing the two inductors with a single equivalent inductor $L_{\mathrm{cq}} .$ How is the emf in the series equivalent related to the emfs in the two inductors? What about the currents?]