Equivalent capacitance homework problem

Click For Summary
SUMMARY

The discussion focuses on calculating the equivalent capacitance between points A and B in a bridge circuit involving capacitors of 3μF, 5μF, 4μF, and 2μF. The user initially calculated the equivalent capacitance as 4μF but found a discrepancy with the textbook answer of 10/3μF. The conversation emphasizes the importance of correctly identifying nodes and understanding that the circuit does not allow for simple series or parallel reductions due to its bridge configuration. Participants suggest using advanced circuit analysis methods such as Y-Delta transformations and Kirchhoff's laws to solve the problem.

PREREQUISITES
  • Understanding of equivalent capacitance in series and parallel configurations.
  • Familiarity with bridge circuits and their properties.
  • Knowledge of Kirchhoff's voltage and current laws (KVL and KCL).
  • Basic concepts of passive linear circuits and voltage dividers.
NEXT STEPS
  • Study Y-Delta and Delta-Y transformations for circuit analysis.
  • Learn about Kirchhoff's laws and their application in complex circuits.
  • Explore the characteristics and analysis techniques for bridge circuits.
  • Practice solving problems involving voltage dividers in both resistive and capacitive circuits.
USEFUL FOR

Students and professionals in electrical engineering, circuit designers, and anyone looking to deepen their understanding of capacitor networks and advanced circuit analysis techniques.

  • #61
gracy said:
But then I get confused which one will be denominator and which one will be numerator.
It doesn't matter which should be numerator or denominator. Just pick any ratio on one side, use the same on the other side.
 
Physics news on Phys.org
  • #62
Let say if I would have taken
C1/C2=C4/C3
After putting the values
I could have thought the bridge is not balanced.
 
  • #63
gracy said:
But then I get confused which one will be denominator and which one will be numerator.
You want to see if the two voltage dividers in the bridge circuit will produce the same voltage division. So a simple procedure is to make ratios of the components that make up each voltage divider. Compare the ratios. You can't go wrong if you select corresponding pairs (use symmetry and common sense).
 
  • #64
gneill said:
You can't go wrong if you select corresponding pairs (
You mean if I have selected C1 as numerator for one potential divider I shall select the one which is adjacent to it but at the other side of bridge as numerator of second potential divider,Right?
 
  • #65
gracy said:
Let say if I would have taken
C1/C2=C4/C3
After putting the values
I could have thought the bridge is not balanced.
You can call the two resistors on one side as 'upper' and 'lower'. So, upper/loewer on one side=upper/lower on the other side.
 
  • Like
Likes   Reactions: gracy
  • #66
cnh1995 said:
You can call the two resistors on one side as 'upper' and 'lower'. So, upper/loewer on one side=upper/lower on the other side.
Its just a memory trick..To understand the bridge balance conceptually, you should analyse it using voltage divider.
 
  • #67
logspot.com%2F-jehPxcGkMYs%2FTfgZWoCbTII%2FAAAAAAAAAQY%2F4eEQrl6bCcQ%2Fs1600%2Fbridge%2Bresistor.gif


upper/lower on one side=upper/lower on the other side.And if bridge is of this sort
proxy.php?image=http%3A%2F%2Fimg.tfd.com%2Fggse%2F4c%2Fgsed_0001_0017_0_img4261.png

upper left/upper right on one side=lower left/lower right on the other side
 
  • #68
gracy said:
logspot.com%2F-jehPxcGkMYs%2FTfgZWoCbTII%2FAAAAAAAAAQY%2F4eEQrl6bCcQ%2Fs1600%2Fbridge%2Bresistor.gif


upper/lower on one side=upper/lower on the other side.And if bridge is of this sort
proxy.php?image=http%3A%2F%2Fimg.tfd.com%2Fggse%2F4c%2Fgsed_0001_0017_0_img4261.png

upper left/upper right on one side=lower left/lower right on the other side
Right. Once you're fluent, you won't need this trick.
 

Similar threads

  • · Replies 4 ·
Replies
4
Views
5K
Replies
2
Views
2K
  • · Replies 11 ·
Replies
11
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 6 ·
Replies
6
Views
3K
  • · Replies 92 ·
4
Replies
92
Views
8K
Replies
108
Views
11K
Replies
5
Views
2K
  • · Replies 3 ·
Replies
3
Views
3K
Replies
4
Views
2K