Understanding Voltage in Parallel RC Circuits

[member 392791]

Hello,

I know that if two resistors are in parallel or two capacitors, they have the same voltage.

However, is it the case that a resistor and capacitor in parallel also have equal voltage?

 

[Meir Achuz]

Yes...

 

[sophiecentaur]

Look up the basics of electrical circuits - Kirchoff's laws etc.. It's all very consistent stuff and the rules apply over a huge range of situations.

 

[Philip Wood]

Think about using a voltmeter to measure the voltage across the resistor or capacitor. You put the probes across the capacitor's wires - but these are connected to the resistor's wires - so you might just as well say that you're connecting the voltmeter across the resistor. There is only one voltage involved, whether you measure it 'across the resistor' or 'across the capacitor'.

 

[sophiecentaur]

Always apply this rule to circuit diagrams: The potential on a wire is the same all the way along it.

So the potential difference between two wires, connecting any number of components, will be the same everywhere. This, of course, may not apply if the wires have resistance or they have a significant length and (high frequency) AC is involved. In this case, a proper circuit diagram should really have included explicit extra resistances and Impedances.