# Capacitance problem

1. Oct 4, 2009

### shrabastee

1. The problem statement, all variables and given/known data
Finding the equivalent capacitance of the supplied circuit.

2. Relevant equations
For parallel capacitors, C EQ.=C1+C2+C3+..
For serial capacitors, 1/C EQ.=1/C1+1/C2+...

3. The attempt at a solution

The circuit simplification is difficult!

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2. Oct 4, 2009

### physicsnoob93

Here, Look at this diagram I drew for you.

It is actually the same circuit.

What can you say about the various potential differences?

Also, take note that the C=Q/V. Over here, C is specified, V and Q are unspecified. How can you make this property useful?

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3. Oct 5, 2009

### shrabastee

Thanks! Just tell me one thing, can C3 be ignored because it carries no charge?

4. Oct 5, 2009

### physicsnoob93

That would be the case if all the capacitors except C3 have an equal capacitance. The potential difference between b and e in the diagram will be 0 and so no current will flow through C3.

The circuit will then be simpler.

And yes, C3 is ignored provided whatever is above is true.

Last edited: Oct 5, 2009