Zhaojie Xu, Teaching Assistant at Texas A&M University, Numerade Educator

07:08

University Physics with Modern Physics

After the current in the circuit of Fig, P30. 71 has reached its final, steady value with switch $S_{1}$ closed and $S_{2}$ open, switch $S_{2}$ is closed, thus short-circuiting the inductor. (Switch $S_{1}$ remains closed. See Problem 30.71 for numerical values of the circuit elements.) (a) Just after $\mathrm{S}_{2}$ is closed, what are $v_{a c}$ and $v_{c b},$ and what are the currents through $R_{0}, R,$ and $S_{2} ?$ (b) A long time after $S_{2}$ is closed, what are $v_{a c}$ and $v_{c b}$ and what are the currents through $R_{0}$ $R,$ and $S_{2} ?$ (c) Derive expressions for the currents through $R_{0}, R$ and $\mathrm{S}_{2}$ as functions of the time $t$ that has elapsed since $\mathrm{S}_{2}$ was
closed. Your results should agree with part (a) when $t=0$ and with part (b) when $t \rightarrow \infty .$ Graph these three currents versus time.

Chapter 30: Inductance