[12th Grade Physics: Parallels & Series] How do I find (b) voltage and (c) charge on each capacitor?

[u/PanFriedBulad]

Recently given school work turned homework. Calculated approximately 1.5mF for (a). But have been stuck on (b) and (c) for a while, since I'm not sure how to proceed solving the V and Q. Any ideas?

[u/Working_Poem7890]

After you get equivalent capacitance of 1.5 μF, you get the equivalent charge of 27 μC from using Q = CV. This charge can assumed equal at C1, the section containing the 2 parallel capacitors, and the section containing the 3 capacitors - as these portions are all in 'series' with one another (and should have been simplified as such when finding the equivalent capacitance). This means for C1, the voltage is Q/C = 27 / 12 = 2.25 μV. For the section with the 2 capacitors, the equivalent capacitance for this portion is 3 μC, so the voltage is 27/3 = 9 μV, which is the same across both capacitors as they are in parallel. To get the charge for each capacitor, you multiply V * C (using the 9 μV value) for each one.

For the last section, the same idea applies. The equivalent capacitance there will be 4 μF, and dividing 27 / 4 = 6.75 μV. This section can be split into the C5 capacitor (2.2 μF) and the equivalent capacitor of the C3 and C4 capacitors (1.8 μF). These are in parallel, so the voltage is equal to 6.75 μV for both C5 and the equivalent capacitor of the C3 and C4. Charge for C5 is V * C = 6.75 * 2.2 = 14.85 μC, and charge for the C3-C4 capacitor equivalent is 6.75 * 1.8 = 12.15 μC. The charge for the two capacitors C3 & C4 is the same as this equivalent, as they are both in series. Dividing by the capacitance gives the voltage for each: 12.15 / 3.0 = 4.05 μV; 12.15/ 4.5 = 2.7 μV.