CHAPTER 8 BASIC RL AND RC CIRCUITS
47. For the circuit given in Fig. 8.78, (a) determine $v_L(0^-)$, $v_L(0^+)$, $i_L(0^-)$, and
$i_L(0^+)$; (b) calculate $i_L(150\text{ ns})$. (c) Verify your answer to part (b) with an
appropriate PSpice simulation.
+
2u(t) mA
25 ?
100 ?
v_L
i_L
3 ?H
? FIGURE 8.78
48. The circuit depicted in Fig. 8.79 contains two independent sources, one of
which is only active for $t > 0$. (a) Obtain an expression for $i_L(t)$ valid for all $t$
(b) calculate $i_L(t)$ at $t = 10\text{ ?s}$, $20\text{ ?s}$, and $50\text{ ?s}$.