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If I have a source between two resistors in series, can I just add the resistors and place the source below,under them? If I have some element in parallel like a capacitor, between two resistors in parallel, are the resistors still in parallel?

If so why?

schematic

simulate this circuit – Schematic created using CircuitLab

Is it the same as:

schematic

simulate this circuit

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3 Answers 3

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On a schematic, wires are perfect and have zero impedance, so both schematics are exactly the same. On a schematic, the goal is maximum clarity. It doesn't matter that it looks different than your board, as long as you arrange it in the way that is easiest to understand.

In a real circuit, wires and traces have resistance and impedance, so if they are long enough, the way stuff is organized can matter. It depends on the currents, frequencies, type of circuit, etc.

If this was the case here, the person in charge of the schematic would write a note next to the components for the person doing the layout.

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Yes, the resistors are still in parallel.

I like to define "in parallel" two different ways. First, if you can see that both terminals (i.e. the ends) of the elements are connected together then the elements are in parallel. Second, if the voltage across the two elements must be the same simply because of how they are connected, then they are connected in parallel. An important point to remember is that elements connected in parallel must have the same voltage across them.

So, all of the elements...the resistors, the capacitor, and the current source...in both of your schematic are in parallel. This is a single node pair circuit, and the voltage must be the same across all of the elements. Parallel elements can be interchanged without changing the behavior of the circuit, as long as they remain connected in parallel.

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Two dipoles are in parallel if you can draw a closed loop going through those elements and nothing else. It doesn't matter how close together they are on a schematic, whether they have neighbors, or whether they are actually drawn in a parallel arrangement or at an angle. What matters is that exactly the same voltage is applied to both at all times.

Two dipoles are in series if they have a common connection point which has no other connections. Again, the actual geometrical layout of the schematic or the presence of neighbors on other terminals doesn't matter. What matters is that exactly the same current flows though both at all times.

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