Question

Are both of these capacitor circuit reductions method valid?

Answer 1

Here is the figure given from the question

Answer 2

I tried reducing the first two left circuits as parallel, then reducing the two right circuits as parallel, then finally combined together as series. Is this an invalid way of doing it?

The online homework system says that the answer is not correct, and to use the below method.

Answer 3

If the first method is invalid, then why?

Answer 4

I'm not quite sure what you're doing in your process. However, I can show you how to do it, and you can compare it to what you did. Is that alright?

Answer 5

Sure

Answer 6

Oh, I see. The first approach you took is incorrect because there isn't a connection between the capacitors.

We'd need an extra connection where that dotted line is. This would allow us to treat the parallel capacitors as parallel to one another.

Without that, we first have to find the equivalent capacitance of the top and bottom first.

Answer 7

Ahhh, I understand. Because the top right capacitor will receive a difference amount of current than the bottom right.

Answer 8

So we can't treat the top left and bottom left as one circuit.

Answer 9

Right. Always start (when finding any equivalent capacitance, resistance, etc) with the "smallest" equivalence