# Equivalent capacitance for polarized capacitors

I understand that capacitors in:

1. Series are combined by doing $$\frac{1}{C_T} = \frac{1}{C_1} + \frac{1}{C_2} + ...$$
2. Parallel are combined by doing $${C_T} = {C_1} + {C_2} + ...$$

I am confused by the negative voltages on the capacitors since these are polarized. How would I go about solving this?

The symbols do indicate that these capacitors are polarity sensitive. Elecrolytic, for example, appear as $$\0\Omega\$$ when reverse biased. Therefore the reverse voltage should be zero, definately not the voltages shown on the diagram.

This diagram is wrong and so the final capacitance cannot be calculated without making some assumptions or changing the problem.

1. Not solvable
2. Solve for the total capacitance before the voltage is applied.
3. Treat all reverse biassed capacitors as $$\0\Omega\$$ until they get destroyed.
4. Treat all reverse biassed capacitors as open because they are already destroyed.

1 and 2 are the best choices.

But I am confused by the negative voltages on the capacitors since these are polarized. how would I go about solving this?

Notice that there is no route for any current to flow in your circuit diagram so, the terminal voltage on the circles to the left of your diagram will be what it will be.

Equivalent Capacitance

However, the equivalent capacitance has nothing to do with how those capacitors are charged and therefore you should ignore the charged voltages because, they are irrelevant for calculating equivalent capacitance at the terminals on the left of your diagram.