일반물리학 2 — Induction and Inductance: Problem 18

18 The switch in Fig. 30-15 is closed on a at time \(t = 0\). What is the ratio \(\mathcal{E}_L / \mathcal{E}\) of the inductor’s self-induced emf to the battery’s emf (a) just after \(t = 0\) and (b) at \(t = 3.50\tau_L\)? (c) At what multiple of \(\tau_L\) will \(\mathcal{E}_L / \mathcal{E} = 0.250\)?