RLC second order circuits

  • Engineering
  • Thread starter paulmdrdo
  • Start date
  • #1
68
2

Homework Statement


2qcgodf.png

Homework Equations


V(t) = V(∞)+( V(0+) - V(∞) )e^-t/τ

3. The Attempt at a Solution

11tml2e.png

Hello again! I've already solved the problem depicted in the picture above and below are the following unknowns that I managed to solved:
205fdi0.png

These results checked out with the answers supplied by the book. By I could not make sense out of these results. For example how come that at t=0+ the rate of change of the voltage across the 2-ohm resistor is dVr(0+)/dt = 2/3 v/s, when in fact the expression for the voltage across it is Vr(t)=4 V ----> this is a constant value how come it has a rate of change of some sort? Same confusion I have with the rate of change of voltage across the capacitor because Vc(t)=-20v.

Please enlighten me with this matter. Thank you!
 

Attachments

Answers and Replies

  • #2
rude man
Homework Helper
Insights Author
Gold Member
7,834
785
What reasoning led you to conclude constant voltages for the 2 ohm and C? When the switch is closed for the 3A supply, everything starts to move - all voltages, all currents!
 

Related Threads on RLC second order circuits

Replies
0
Views
3K
Replies
8
Views
2K
Replies
14
Views
3K
Replies
1
Views
6K
Replies
3
Views
5K
  • Last Post
Replies
3
Views
716
  • Last Post
Replies
0
Views
829
  • Last Post
Replies
9
Views
2K
Top