Thevenin AC circuit

  • Engineering
  • Thread starter dwn
  • Start date
  • #1
dwn
165
2

Homework Statement



Image Attached

Homework Equations



Thevenin, Series, Parallel

The Attempt at a Solution



j10(12-j34) / (j10+12-j34) = (340 + 120j) / (12/j24)

1.67 + j13.3 or 13.44∠82.4°

Now why can't I just use this equivalent resistance and multiply by the current source (22∠30°) to find the Thevenin Voltage? The result of doing this is 295.68∠112.8°V. Instead, the book uses Nodal Analysis to find VTH, which results in 295.3∠115.889°V.
Why do the voltages roughly match, but the phase angles do not? Do you think book made mistake?
 

Attachments

  • Screen Shot 2014-05-25 at 7.00.24 PM.jpg
    Screen Shot 2014-05-25 at 7.00.24 PM.jpg
    3.3 KB · Views: 397

Answers and Replies

  • #2
gneill
Mentor
20,925
2,867

Homework Statement



Image Attached

Homework Equations



Thevenin, Series, Parallel

The Attempt at a Solution



j10(12-j34) / (j10+12-j34) = (340 + 120j) / (12/j24)

1.67 + j13.3 or 13.44∠82.4°

Now why can't I just use this equivalent resistance and multiply by the current source (22∠30°) to find the Thevenin Voltage? The result of doing this is 295.68∠112.8°V. Instead, the book uses Nodal Analysis to find VTH, which results in 295.3∠115.889°V.
Why do the voltages roughly match, but the phase angles do not? Do you think book made mistake?

Your analysis looks okay. It's quite possible for a text to have a typo or mistake. If the book presents all the steps of their solution, perhaps you can spot where their error has occurred.
 

Related Threads on Thevenin AC circuit

Replies
2
Views
8K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
1
Views
1K
  • Last Post
Replies
6
Views
764
Replies
8
Views
2K
Replies
12
Views
997
Replies
1
Views
493
Top