ECE $201$

Circuit Theory I

D$.$ Kasilingam

Mid Term II $-$ November $2023$

$1.$

Figure $1.$

Figure $1$ shows a circuit with a current source, three resistors, an inductor and a switch. All the resistance and inductance values, except the current source I $0,$ are given in the figure. The source current I $0$ is unknown. For $\backslash ($ t $\backslash$leq $0\backslash ),$ the switch remains closed for a long time. The switch is opened at $\backslash ($ t$=0\backslash )$ and remains open after that. When the switch is closed for $\backslash ($ t $\backslash$leq $0\backslash ),$ the current in the inductor, L$1,$ is in steady state. Note in the steady state, an inductor acts like a short circuit. Also, the current in an inductor cannot change instantaneously. All the questions below apply to this circuit.

$($a$)$ When the switch remains closed for $\backslash ($ t $\backslash$leq $0\backslash ),$ the current through R$1$ is $0\mathrm{.}5$ mA $.$ Find the voltage across R$1.(5)$