Current in an RL-circuit The accompanying diagram represents an electrical circuit whose total resistance is a constant R ohms and whose self-inductance, shown as a coil, is L henries, also a constant. There is a switch whose terminals at a and b can be closed to connect a constant electrical source of V volts. From Section 9.2, we have
$$L \frac{d i}{d t}+R i=V$$
where i is the current in amperes and t is the time in seconds.
Use a phase line analysis to sketch the solution curve assuming that the switch in the $R L$ -circuit is closed at time $t=0$ . What happens to the current as $t \rightarrow \infty ?$ This value is called the
-state solution.