The switch in FIGURE P34.80 has been open for a long time. It is closed at $t=0 \mathrm{s}$
a. After the switch has been closed for a long time, what is the current in the circuit? Call this current $I_{0}$.
b. Find an expression for the current $I$ as a function of time. Write your expression in terms of $I_{0}, R,$ and $L$
c. Sketch a current-versus-time graph from $t=0$ s until the current is no longer changing.