How Do You Calculate the Charge on a Capacitor in Series?

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To calculate the charge on a capacitor in series, the equivalent capacitance must first be determined using the formula 1/C = 1/C1 + 1/C2 + 1/C3. The user initially calculated an incorrect equivalent capacitance of approximately 0.435 μF. The correct equivalent capacitance for the three capacitors (8 μF, 9 μF, and 5 μF) connected in series needs to be recalculated. Once the correct equivalent capacitance is found, the charge can be calculated using Q = C * E, where E is the voltage of the battery. Accurate calculations are essential for determining the charge on the positive plate of the 9 μF capacitor.
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Homework Statement



Three capacitors of capacitance 8, 9, and 5 μF respectively, are connected in series to a 4 V battery. What is the charge on the positive plate of the 9 μF capacitor?


Homework Equations



Q = C*E
1/C = 1/C1 + ..

The Attempt at a Solution



I drew out the circuit it would make. I know that to calculate C it is 1/C = 1/C1+1/C2...
I took the general equation for Q= C*E. I did this and got 1.74 uC. But, this is not correct. Could you tell me where I am going wrong?
 
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Hi purduegirl,

You calculation of the equivalent capacitance is wrong. Your post does not have many numbers, but you seem to have calculated that the equivalent capacitance was about 0.435 \muF, but that is not what 1/C = 1/C1+1/C2... gives.

Do you see what went wrong, and what the equivalent capacitance should be?
 

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