# Is a Resistor from V+ to Gnd Considered Parallel or Series?

Joined Oct 26, 2012
282
This image shows parallel and series with multiple resistors. But, if there's only ONE resistor, it will be the identical circuit! So, would we call that "parallel" or "series"?

thx

#### WBahn

Joined Mar 31, 2012
26,398
But, if there's only ONE resistor, it will be the identical circuit! So, would we call that "parallel" or "series"?
Yes.

If there are only two components (a resistor and a power source in this case) then it is both in series and in parallel.

Two components are in series if and only if any current flowing in one must flow in the other. So they are in series.

Two components are in parallel if and only if any voltage appearing across one must appear across the other. So they are in parallel.

This is known as a degenerate case where the distinctions between the two vanish.

• Joined Oct 26, 2012
282
Wow! Ok, then with just one resistor, is it a IV converter, or VI converter? Both....?

Joined Apr 16, 2011
536
Can be either, depending on whether you give it a constant V or a constant I

Constant V is a far more common occurrence (such as from a battery) than constant I.

Constant I is starting to become more common, for driving LEDs.

Whilst thinking of a resistor as VI or IV converter might be valid, it is a very unusual way to think about a resistor.

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#### OBW0549

Joined Mar 2, 2015
3,566
But, if there's only ONE resistor, it will be the identical circuit! So, would we call that "parallel" or "series"?
Neither. Since in that case there's no distinction between the two, just call it what it is: merely a resistor connected across a voltage source.

#### BR-549

Joined Sep 22, 2013
4,938

#### WBahn

Joined Mar 31, 2012
26,398
Wow! Ok, then with just one resistor, is it a IV converter, or VI converter? Both....?
Depending on the context, either way may be a reasonable view. Of course, that applies to all resistors regardless of connection topology since the relationship between V and I is a characteristic of the device, not the connections.

#### AllanGH

Joined Oct 1, 2013
19
Consulting Schrödinger's favorite oracle, the answer is that it is simultaneously neither, and both...until you take measurements:

If you measure the current through the resistor, then it is a series circuit.
If you measure the voltage across the resistor, then it is a parallel circuit.

Seriously...give it a try.

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