Solution Found!
The circuit shown in Figure P 7.4-9 is at steady state before the switch closes. The
Chapter 7, Problem P7.4-9(choose chapter or problem)
The circuit shown in Figure P 7.4-9 is at steady state before the switch closes. The capacitor voltages are both zero before the switch closes \(\left(v_1(0)=v_2(0)=0\right)\). The current i(t) is given by
\(i(t)=\left\{\begin{array}{cc} 0 \mathrm{~A} & \text { for } t<0 \\ 2.4 e^{-30 \mathrm{r}} \mathrm{A} & \text { for } t>0 \end{array}\right.\)
(a) Determine the capacitor voltages \(v_1(t)\) and \(v_2(t)\) for \(t \geq 0\).
(b) Determine the energy stored by each capacitor 20 ms after the switch closes.
The series capacitors can be replaced by an equivalent capacitor.
(c) Determine the voltage across the equivalent capacitor, + on top, for \(t \geq 0\).
(d) Determine the energy stored by the equivalent capacitor 20 ms after the switch closes.
Questions & Answers
QUESTION:
The circuit shown in Figure P 7.4-9 is at steady state before the switch closes. The capacitor voltages are both zero before the switch closes \(\left(v_1(0)=v_2(0)=0\right)\). The current i(t) is given by
\(i(t)=\left\{\begin{array}{cc} 0 \mathrm{~A} & \text { for } t<0 \\ 2.4 e^{-30 \mathrm{r}} \mathrm{A} & \text { for } t>0 \end{array}\right.\)
(a) Determine the capacitor voltages \(v_1(t)\) and \(v_2(t)\) for \(t \geq 0\).
(b) Determine the energy stored by each capacitor 20 ms after the switch closes.
The series capacitors can be replaced by an equivalent capacitor.
(c) Determine the voltage across the equivalent capacitor, + on top, for \(t \geq 0\).
(d) Determine the energy stored by the equivalent capacitor 20 ms after the switch closes.
ANSWER:
Step 1 of 5
a)
Voltage across a capacitor equals:
Voltage 
=
=
=
=
Voltage 
=
=
=
=
