How Do You Find Equivalent Capacitance in This Complex Circuit?

[majormaaz]

Homework Statement

In Fig. 26-32, the battery has a potential difference of 20 V.
http://www.webassign.net/hrw/26_32.gif

Homework Equations

If Capacitors are in series, then (1/C1) + (1/C2) = (1/Cnew)
If Capacitors are in parallel, then you just add them, C1 + C2 = Cnew

The Attempt at a Solution

I'm not sure how to get the equivalent capacitance from here.
Would I just add the 12/7 to the 2uF parallel from it to make one capacitor? What happens then to the 2uF originally in series with the 12/7 uF?
This is what I did: Combine the 3 and 4 uF capacs, then the 12/7 and 2 uF(parallel), then that and 3 uF (series) and then that with the remaining 2 uF and 3 uF, in series.
I ended up with 0.696, which is apparently wrong. Is there a correct way how to resolve all these capacitors? PEMDAS for circuits? Any help will be appreciated

 

[majormaaz]

Here's a picture showing where I'm stuck at:

 

[phinds]

Uh ... how did you get 4 in series with 4 = 12/7 ?

 

[majormaaz]

Uh ... how did you get 4 in series with 4 = 12/7 ?

...Thaaaat appears to be my problem. Thanks! I'll have a go at this again

 

[majormaaz]

So, I did the work again, fixing that 3 uF into a 4 uF, and I ended up with getting 12/17 uF, but that's not right either.
Could somebody advise me as to which branches/capacitors I should deal with first, and so on?

 

[NascentOxygen]

So, I did the work again, fixing that 3 uF into a 4 uF, and I ended up with getting 12/17 uF, but that's not right either.

Are you using a calculator?

It is pretty obvious when capacitors are in series, so you might as well start there. (But it doesn't matter where you start.) Re-draw the circuit after each step.

So you have 2x 4µF in series, what equivalent capacitance is that?

I can see a pair of 3µF in parallel.

 

[phinds]

So, I did the work again, fixing that 3 uF into a 4 uF, and I ended up with getting 12/17 uF, but that's not right either.
Could somebody advise me as to which branches/capacitors I should deal with first, and so on?

You need to show your work so we can see how it is that you are getting these nonsensical answers

Show step by step how you reduce two 4-uf's in series to a single equivalent cap.

 

[majormaaz]

I hope this picture helps! It goes from left to right, just in case you didn't know.
EDIT: Sorry, wrong picture

 

[majormaaz]

Here we go! My REVISED work.

 

[phinds]

You KEEP not showing your work, just the end results of each step. Let me repeat myself:

You need to show your work so we can see how it is that you are getting these nonsensical answers

 

[NascentOxygen]

You overlooked my hint? ("I can see a pair of 3µF in parallel")