# Potential difference across each capacitor

#### w3390

1. The problem statement, all variables and given/known data
How many 1 microF capacitors connected in parallel would it take to store a total charge of 1 mC if the potential difference across each capacitor is 10.0V?

2. Relevant equations
C=Q/V
in parallel --> Ceq=C1+C2+C3...

3. The attempt at a solution
I attemped this problem by first using the equation C=Q/V, using 1mC as my Q and 10V as my V. This gave me a total capacitance of 1*10^-4 F. I then divided this number by the capacitance of a single capacitor, 1*10^-6. This result showed that it would take 100 capacitors. I thought this answer seemed reasonable, but the next sentence in the problem tells me to diagram the parallel combination. I don't think they want me to draw out 100 capacitors in parallel. Can anyone double check my answer and tell me if it is correct?

#### LowlyPion

Homework Helper
Re: capacitance

If you can write an equation like "Ceq=C1+C2+C3... skip a few +C100", what is your hesitancy in making a drawing like that?

#### tiny-tim

Homework Helper
Hi w3390! … if the potential difference across each capacitor is 10.0V?
erm each capacitor! #### w3390

Re: capacitance

If you can write an equation like "Ceq=C1+C2+C3... skip a few +C100", what is your hesitancy in making a drawing like that?

If I do trust my math, I will be drawing out 100 capacitors on parallel on my sheet of paper. Does this sound reasonable to you?

#### LowlyPion

Homework Helper
Re: capacitance

If I do trust my math, I will be drawing out 100 capacitors on parallel on my sheet of paper. Does this sound reasonable to you?
Sounds tedious when an ellipsis will do.

#### w3390

Re: capacitance

Does this mean that the potential difference across the entire combination will be 1000V by multiplying the number of capacitors by the drop across each one?

Never mind, I figured it out. Thanks.

Last edited:

#### tiny-tim

Homework Helper
Yes, but it's not 1000V … call the number of capacitors n, and see how many times n comes into the equation. #### mplayer

Re: capacitance

I'm getting 1x10^-5 F for total capacitance. So 10 of the 1microF capacitors in parallel. Assuming you meant "total charge of 1mC" to mean micro-Coulomb and not milli-Coulomb. Otherwise it's like 10,000 capacitors. ### The Physics Forums Way

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